layout: Expose some non-interactive accessibility roles based on DOM node type. (#44255)

Sets the accessibility role of nodes based on their DOM node type
(ignoring ARIA roles and computed styles for now), for a small subset of
roles.

This change also re-works some details of accessibility tree building:
- Set the `root` property for the accesskit tree to the node ID for the
root DOM node, rather than creating a placeholder root node which
contains the root DOM node.
- Since we now map the `<body>` node to the `RootWebArea` role, this
required a small change to the accessibility test logic to do a tree
walk to find the `RootWebArea` node, which used to be the first child
since we artificially set the placeholder root node to be the
`RootWebArea` node.
- Have `update_node_and_children()` return a bool indicating whether any
node was updated.
- Split the code updating the node itself into its own function,
`update_node()`, which takes a DOM node and returns a tuple containing
the accessibility node ID and a bool indicating whether the node
required updating
- Add an `assert_node_by_id()` method to retrieve an accessibility node
based on its ID.

Testing: See new tests added in this PR.

---------

Signed-off-by: Alice Boxhall <alice@igalia.com>
Co-authored-by: delan azabani <dazabani@igalia.com>

.config/nextest.toml

@@ -1,6 +1,7 @@
 [profile.default]
 # Print a slow warning after period, terminate unit-test after 4x period.
 slow-timeout = { period = "5s", terminate-after = 4 }
+status-level = "leak"
 
 [profile.ci]
 fail-fast = false

.devcontainer/Ubuntu.Dockerfile

@@ -14,6 +14,9 @@ RUN apt-get update \
     &&  /tmp/linux_packages/generate_pkg_list.sh /tmp/linux_packages/apt/* | xargs apt-get install -y --no-install-recommends \
     && curl --version
 
+# Required due to https://github.com/servo/servo/issues/35029
+RUN apt purge -y fonts-droid-fallback
+
 # Please keep `RUST_VERSION` in sync with the `rust-toolchain.toml` file.
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \

.devcontainer/devcontainer.json

@@ -16,9 +16,17 @@
 	"postCreateCommand":
 		"./mach bootstrap --yes",
 
+	"mounts": [
+		"source=servo-cargo-target,target=/var/servo-cargo-target,type=volume"
+	],
+
 	"containerEnv": {
 		"CC": "clang",
 		"CXX": "clang++",
+		// at least on macOS the workspace directory can be mounted as case-insensitve,
+		// which causes build errors in mozjs. Using a volume avoids this issue, and can
+		// also improve performance.
+		"CARGO_TARGET_DIR": "/var/servo-cargo-target",
 		"UV_PROJECT_ENVIRONMENT": ".devcontainer-venv"
 	}
 }

.github/CODEOWNERS

@@ -39,6 +39,10 @@
 # Reviewers for XPath related code
 /components/xpath @simonwuelker
 
+# Reviewers for DevTools
+/components/devtools @atbrakhi @eerii
+/components/shared/devtools @atbrakhi @eerii
+
 # Reviewers for CI related code
 /.github/workflows @sagudev
 /.github/actions @sagudev

.github/ISSUE_TEMPLATE/roadmap.md

@@ -0,0 +1,25 @@
+---
+name: Roadmap Issue
+about: Create an issue to track in the Servo roadmap
+title: ''
+labels: B-roadmap
+assignees: ''
+
+---
+
+## Roadmap Issue
+
+**Description:**
+A clear and concise description of the work that will be done.
+
+**Area:** e.g. Layout, Script, Performance, ...
+
+**People:** Who are planning to work on this task.
+
+Leave it blank if it's just something interesting for the project,
+but nobody is planning to work on at the moment.
+
+---
+
+Feel free to add any other comments on the issue after this line.
+

.github/dependabot.yml

@@ -52,6 +52,11 @@ updates:
     objc2-related:
       patterns:
         - "objc2*"
+    rustls-webpki-related:
+      patterns:
+        - rustls-webpki
+        - webpki-roots
+        - webpki-root-certs
     sea-query-related:
       patterns:
         - "sea-query"

.github/workflows/book-export.yml

@@ -9,6 +9,9 @@ jobs:
     # Run job only on servo/servo
     if: github.repository == 'servo/servo'
     runs-on: ubuntu-latest
+    environment:
+      name: book-sync
+      deployment: false
     steps:
       - name: Check out Servo
         uses: actions/checkout@v6

.github/workflows/docker.yml

@@ -1,4 +1,3 @@
-#
 name: Build Docker image and push to GitHub Packages
 
 # This workflow file is adapted from the example at https://docs.github.com/en/packages/managing-github-packages-using-github-actions-workflows/publishing-and-installing-a-package-with-github-actions#upgrading-a-workflow-that-accesses-a-registry-using-a-personal-access-token
@@ -7,46 +6,123 @@ on:
     branches:
       - main
     # Only rebuild if the Dockerfile or dependencies change.
-    paths:
+    paths: &container-paths
       - '.devcontainer/**'
       - 'python/servo/platform/linux_packages/**'
+      - '.github/workflows/docker.yml'
   workflow_dispatch:
+  pull_request:
+    branches:
+      - main
+    paths: *container-paths
+
+env:
+  IMAGE_NAME: devcontainer-ubuntu
+  IMAGE_DOWNLOAD_PATH: docker-image-artifacts
+  # AMD64 and ARM64 label names are what docker chose
+  AMD64_IMAGE_ARCHIVE: devcontainer-ubuntu-amd64.tar
+  ARM64_IMAGE_ARCHIVE: devcontainer-ubuntu-arm64.tar
+  AMD64_IMAGE_ARTIFACT_NAME: devcontainer-ubuntu-image-amd64
+  ARM64_IMAGE_ARTIFACT_NAME: devcontainer-ubuntu-image-arm64
 
 jobs:
-  devcontainer_ubuntu:
-    runs-on: ubuntu-latest
-    # We probably don't want to spam the package registry of every developer
-    # thats working on servo and has actions enabled on their fork.
-    # You can comment this if to test changes to the workflow locally in your fork,
-    # use manual workflow dispatch in your fork.
-    if: github.repository_owner == 'servo' || github.event_name == 'workflow_dispatch'
+  devcontainer_ubuntu_build:
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - arch: amd64
+            platform: linux/amd64
+            runner: ubuntu-24.04
+            image_archive: devcontainer-ubuntu-amd64.tar
+            image_artifact_name: devcontainer-ubuntu-image-amd64
+          - arch: arm64
+            platform: linux/arm64
+            runner: ubuntu-24.04-arm
+            image_archive: devcontainer-ubuntu-arm64.tar
+            image_artifact_name: devcontainer-ubuntu-image-arm64
     permissions:
-      packages: write
       contents: read
-    env:
-      IMAGE_NAME: devcontainer-ubuntu
     steps:
       - uses: actions/checkout@v6
 
-      - name: Build image
-        run: docker build . --file .devcontainer/Ubuntu.Dockerfile --tag ${{ env.IMAGE_NAME }} --label "runnumber=${GITHUB_RUN_ID}"
-
-      - name: Log in to registry
-        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
-
-      - name: Push image
+      - name: Build ${{ matrix.arch }} image
         run: |
-          IMAGE_ID=ghcr.io/${{ github.repository_owner }}/servo/$IMAGE_NAME
+          docker build . \
+            --file .devcontainer/Ubuntu.Dockerfile \
+            --platform ${{ matrix.platform }} \
+            --tag ${{ env.IMAGE_NAME }}:${{ matrix.arch }} \
+            --label "runnumber=${GITHUB_RUN_ID}"
+
+      - name: Save ${{ matrix.arch }} image
+        if: github.event_name != 'pull_request'
+        run: docker save --output "${{ matrix.image_archive }}" "${{ env.IMAGE_NAME }}:${{ matrix.arch }}"
+
+      - name: Upload ${{ matrix.arch }} image artifact
+        if: github.event_name != 'pull_request'
+        uses: actions/upload-artifact@v7
+        with:
+          name: ${{ matrix.image_artifact_name }}
+          path: ${{ matrix.image_archive }}
+          archive: false
+          if-no-files-found: error
+
+  devcontainer_ubuntu_publish:
+    runs-on: ubuntu-24.04
+    needs:
+      - devcontainer_ubuntu_build
+    # Use manual workflow dispatch in your fork to test changes.
+    if: (github.event_name == 'push' && github.repository_owner == 'servo') || github.event_name == 'workflow_dispatch'
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/download-artifact@v8
+        with:
+          path: ${{ env.IMAGE_DOWNLOAD_PATH }}
+          merge-multiple: true
+
+      - name: List downloaded image artifacts
+        run: ls -R "${{ env.IMAGE_DOWNLOAD_PATH }}"
+
+      - name: Derive image metadata
+        id: image_meta
+        run: |
+          IMAGE_ID=ghcr.io/${{ github.repository_owner }}/servo/${{ env.IMAGE_NAME }}
 
           # This changes all uppercase characters to lowercase.
-          IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
+          IMAGE_ID=$(echo "$IMAGE_ID" | tr '[A-Z]' '[a-z]')
           # This strips the git ref prefix from the version.
           VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
 
           # This uses the Docker `latest` tag convention.
-          [ "$VERSION" == "main" ] && VERSION=latest
-          echo IMAGE_ID=$IMAGE_ID
-          echo VERSION=$VERSION
-          # Todo: It would be nice to add another tag here, that has a version number, or a date-tag.
-          docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
-          docker push $IMAGE_ID:$VERSION
+          [ "$VERSION" = "main" ] && VERSION=latest
+          
+          echo "IMAGE_ID=$IMAGE_ID"
+          echo "VERSION=$VERSION"
+
+          echo "image_id=$IMAGE_ID" >> "$GITHUB_OUTPUT"
+          echo "version=$VERSION" >> "$GITHUB_OUTPUT"
+          echo "multiarch_tag=$IMAGE_ID:$VERSION" >> "$GITHUB_OUTPUT"
+
+      - name: Log in to registry
+        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
+
+      - name: Push platform images and publish manifest list
+        run: |
+          for archive in "${{ env.AMD64_IMAGE_ARCHIVE }}" "${{ env.ARM64_IMAGE_ARCHIVE }}"; do
+            docker load --input "${{ env.IMAGE_DOWNLOAD_PATH }}/$archive"
+          done
+
+          IMAGE_TAGS=()
+
+          for arch in amd64 arm64; do
+            IMAGE=${{ steps.image_meta.outputs.image_id }}:$arch-${{ steps.image_meta.outputs.version }}
+            IMAGE_TAGS+=("$IMAGE")
+            docker tag ${{ env.IMAGE_NAME }}:$arch "$IMAGE"
+            docker push "$IMAGE"
+          done
+
+          # This pushes to the registry
+          docker buildx imagetools create --tag ${{ steps.image_meta.outputs.multiarch_tag }} "${IMAGE_TAGS[@]}"

.github/workflows/linux.yml

@@ -145,7 +145,9 @@ jobs:
       - name: Change Mirror Priorities
         if: ${{ runner.environment != 'self-hosted' }}
         uses: ./.github/actions/apt-mirrors
-      - uses: taiki-e/install-action@v2
+      - name: Install cargo nextest
+        if: ${{ inputs.unit-tests }}
+        uses: taiki-e/install-action@v2
         with:
           tool: nextest
       - name: Bootstrap dependencies
@@ -155,7 +157,7 @@ jobs:
           sudo apt update
           echo "wireshark-common wireshark-common/install-setuid boolean true" | sudo debconf-set-selections
           sudo apt install -qy tshark
-          ./mach bootstrap --yes --skip-lints
+          ./mach bootstrap --yes --skip-lints --skip-nextest
 
       # Always install crown, even on self-hosted runners, because it is tightly
       # coupled to the rustc version, and we may have the wrong version if the
@@ -287,6 +289,7 @@ jobs:
           # lld seems to use less memory and prevents OOM errors during linking.
           # We can remove this after upgrading to Rust 1.90, where lld will be the default.
           RUSTFLAGS: "-C link-arg=-fuse-ld=lld"
+          LLVM_OBJDUMP: llvm-objdump-14
         run: |
           cargo +${{ steps.msrv.outputs.rust_version }} build -p servo --locked
 

.github/workflows/mac-arm64.yml

@@ -109,9 +109,11 @@ jobs:
       - if: ${{ runner.environment == 'self-hosted' }}
         # Same as `git switch --detach FETCH_HEAD`, but fixes up dirty working
         # trees, in case the runner image was baked with a dirty working tree.
+        # Safeguard: -- means FETCH_HEAD is revision instead of path.
+        # See <https://github.com/servo/servo/pull/44309>
         run: |
           git switch --detach
-          git reset --hard FETCH_HEAD
+          git reset --hard FETCH_HEAD --
 
       - if: runner.environment != 'self-hosted'
         name: Setup Python
@@ -125,14 +127,16 @@ jobs:
       - name: Install crown
         run: cargo install --path support/crown
 
-      - uses: taiki-e/install-action@v2
+      - name: Install cargo nextest
+        if: ${{ inputs.unit-tests }}
+        uses: taiki-e/install-action@v2
         with:
           tool: nextest
 
       - if: runner.environment != 'self-hosted'
         name: Bootstrap
         run: |
-          ./mach bootstrap --yes --skip-lints
+          ./mach bootstrap --yes --skip-lints --skip-nextest
           brew install gnu-tar
       - name: Build (${{ inputs.profile }})
         run: |

.github/workflows/mac.yml

@@ -126,14 +126,16 @@ jobs:
       - name: Install crown
         run: cargo install --path support/crown
 
-      - uses: taiki-e/install-action@v2
+      - name: Install cargo nextest
+        if: ${{ inputs.unit-tests }}
+        uses: taiki-e/install-action@v2
         with:
           tool: nextest
 
       - if: runner.environment != 'self-hosted'
         name: Bootstrap
         run: |
-          ./mach bootstrap --yes --skip-lints
+          ./mach bootstrap --yes --skip-lints --skip-nextest
           brew install gnu-tar
       - name: Build (${{ inputs.profile }})
         run: |

.github/workflows/ohos.yml

@@ -182,9 +182,11 @@ jobs:
         run: git fetch --depth=1 origin $GITHUB_SHA
       - if: ${{ github.event_name == 'pull_request_target' }}
         run: git fetch --depth=1 origin ${{ github.event.pull_request.head.sha }}
+      # Safeguard: -- means FETCH_HEAD is revision instead of path.
+      # See <https://github.com/servo/servo/pull/44309>
       - run: |
           git switch --detach
-          git reset --hard FETCH_HEAD
+          git reset --hard FETCH_HEAD --
       - name: Adding test files to directory
         run: cp -r support/hitrace-bencher/* support/openharmony/AppScope/resources/resfile/
       - name: Build for aarch64 HarmonyOS

.github/workflows/release.yml

@@ -13,6 +13,10 @@ on:
         description: '`true` to create a release on this repo, false to release to the nightly-releases repo'
         type: boolean
         default: false
+      crates_io:
+        description: '`true` to publish to crates.io'
+        type: boolean
+        default: false
       release_tag:
         required: true
         type: string
@@ -28,6 +32,9 @@ jobs:
     if: github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch'
     name: Create Draft GH Release
     runs-on: ubuntu-latest
+    environment: &publish-environment
+      name: publish
+      deployment: false
     steps:
       - id: create-release
         run: |
@@ -46,7 +53,7 @@ jobs:
           TEMP_TAG=$(basename "$RELEASE_URL")
           RELEASE_ID=$( \
             gh api -H "Accept: application/vnd.github+json" \
-            -H "X-GitHub-Api-Version: 2022-11-28" \
+            -H "X-GitHub-Api-Version: 2026-03-10" \
             "/repos/${RELEASE_REPO}/releases/tags/${TEMP_TAG}" \
             | jq '.id' \
           )
@@ -66,37 +73,64 @@ jobs:
         && (inputs.regular_release || false) == false
     name: Publish GH Release
     runs-on: ubuntu-latest
+    environment: *publish-environment
     steps:
-      - name: Publish as latest (success)
-        if: ${{ !contains(needs.*.result, 'failure') && !contains(needs.*.result, 'cancelled') }}
+      - name: Publish release (success)
+        if: ${{ !contains(needs.*.result, 'failure') && (!contains(needs.*.result, 'cancelled') && !cancelled()) }}
+        env:
+          MAKE_LATEST: ${{ github.event_name == 'schedule' && 'true' || 'false' }}
         run: |
           gh api \
             --method PATCH \
             -H "Accept: application/vnd.github+json" \
-            -H "X-GitHub-Api-Version: 2022-11-28" \
+            -H "X-GitHub-Api-Version: 2026-03-10" \
             /repos/${RELEASE_REPO}/releases/${RELEASE_ID} \
-            -F draft=false
-      - name: Publish as latest (failure)
-        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+            -F draft=false \
+            -f make_latest="${MAKE_LATEST}"
+      - name: Publish release (failure)
+        if: ${{ contains(needs.*.result, 'failure') || (contains(needs.*.result, 'cancelled') || cancelled()) }}
         run: |
           gh api \
             --method PATCH \
             -H "Accept: application/vnd.github+json" \
-            -H "X-GitHub-Api-Version: 2022-11-28" \
+            -H "X-GitHub-Api-Version: 2026-03-10" \
             /repos/${RELEASE_REPO}/releases/${RELEASE_ID} \
-            -F prerelease=true -F draft=false
+            -F prerelease=true \
+            -F draft=false \
+            -f make_latest=false
     env:
       GITHUB_TOKEN: ${{ inputs.regular_release && github.token || secrets.NIGHTLY_REPO_TOKEN }}
       RELEASE_ID: ${{ needs.create-draft-release.outputs.release-id }}
     needs:
       - create-draft-release
       - upload-vendored-source
-      - upload-linux-nightly
-      - upload-win-nightly
-      - upload-mac-nightly
-      - upload-mac-arm64-nightly
-      - upload-android-nightly
-      - upload-ohos-nightly
+      - upload-artifacts-nightly
+      - upload-artifacts-release
+
+  publish-crates-io:
+    name: 'Publish to crates.io'
+    if: github.repository == 'servo/servo' && (inputs.crates_io || false)
+    environment:
+      name: publish_crates_io
+      deployment: false
+    runs-on: ubuntu-22.04
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/checkout@v6
+      - uses: rust-lang/crates-io-auth-action@v1
+        id: auth
+      - name: Publish to crates.io
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ steps.auth.outputs.token }}
+          SERVO_CRATES_IO_SLEEP_AFTER_PUBLISH_SECONDS: "30"
+          SERVO_CRATES_IO_VERIFY_PUBLISHED_TIMEOUT_SECONDS: "300"
+          SERVO_CRATES_IO_VERIFY_PUBLISHED_INTERVAL_SECONDS: "10"
+        # Verification requires building, which is incredibly slow and also increases our attack surface.
+        # If we decide for an extra verification, we should add a seperate job before this one, which
+        # does a `dry-run` publish without any elevated permissions.
+        run: |
+          python3 etc/ci/publish_crates_io.py --no-verify
 
   build-win:
     # This job is only useful when run on upstream servo.
@@ -113,6 +147,7 @@ jobs:
     if: github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch'
     name: Upload vendored source archive
     runs-on: ubuntu-latest
+    environment: *publish-environment
     permissions:
       contents: write
       id-token: write
@@ -141,45 +176,100 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ inputs.regular_release && github.token || secrets.NIGHTLY_REPO_TOKEN }}
 
-  upload-win-nightly:
+  upload-artifacts-nightly:
     # Only run scheduled nightly builds on upstream servo.
     if: |
       (github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch')
         && (inputs.regular_release || false) == false
+    runs-on: ubuntu-latest
     permissions:
       id-token: write
       attestations: write
-    needs:
+    environment: *publish-environment
+    needs: &upload-artifacts-needs
       - create-draft-release
       - build-win
-    secrets:
-      github_upload_token: ${{ secrets.NIGHTLY_REPO_TOKEN }}
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-win.outputs.artifact_ids }}
-      artifact_platform: windows-msvc
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo:  ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
+      - build-mac
+      - build-mac-arm64
+      - build-linux
+      - build-android
+      - build-ohos
+    strategy: &upload-artifacts-strategy
+      fail-fast: false
+      matrix:
+        include:
+          - artifact_ids: ${{ needs.build-win.outputs.artifact_ids }}
+            artifact_platform: windows-msvc
+          - artifact_ids: ${{ needs.build-mac.outputs.artifact_ids }}
+            artifact_platform: mac
+          - artifact_ids: ${{ needs.build-mac-arm64.outputs.artifact_ids }}
+            artifact_platform: mac-arm64
+          - artifact_ids: ${{ needs.build-linux.outputs.artifact_ids }}
+            artifact_platform: linux
+          - artifact_ids: ${{ needs.build-android.outputs.artifact_ids }}
+            artifact_platform: android
+          - artifact_ids: ${{ needs.build-ohos.outputs.artifact_ids }}
+            artifact_platform: ohos
+    env:
+      ARTIFACT_IDS: ${{ matrix.artifact_ids }}
+      ARTIFACT_PLATFORM: ${{ matrix.artifact_platform }}
+      GITHUB_RELEASE_ID: ${{ needs.create-draft-release.outputs.release-id }}
+      RELEASE_REPO: ${{ github.repository_owner }}/servo-nightly-builds
+      RELEASE_REPO_TOKEN: ${{ secrets.NIGHTLY_REPO_TOKEN }}
+      S3_UPLOAD_CREDENTIALS: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
+    steps: &upload-artifacts-steps
+      - uses: actions/checkout@v6
+        with:
+          sparse-checkout: |
+            .github
+            etc/ci
+          fetch-depth: '1'
+      - name: Setup Python
+        uses: ./.github/actions/setup-python
+      - name: Validate artifact IDs
+        run: |
+          if [[ -z "${ARTIFACT_IDS}" ]]; then
+            echo "Error: No artifact IDs provided."
+            echo "Help: Check the build job's outputs.artifact_ids value."
+            echo "If you recently renamed the build job without updating the corresponding output reference,"
+            echo "that is likely the cause of this error."
+            exit 1
+          fi
+      - uses: actions/download-artifact@v8
+        with:
+          artifact-ids: ${{ env.ARTIFACT_IDS }}
+          merge-multiple: true
+          path: release-artifacts
+      - name: Generate artifact attestation
+        uses: actions/attest-build-provenance@v3
+        with:
+          subject-path: 'release-artifacts/*'
+      - name: Upload release artifacts
+        run: |
+          ./etc/ci/upload_nightly.py "${ARTIFACT_PLATFORM}" \
+            --secret-from-environment \
+            --github-release-id "${GITHUB_RELEASE_ID}" \
+            release-artifacts/*
 
-  upload-win-release:
+  upload-artifacts-release:
     if: github.event_name == 'workflow_dispatch' && inputs.regular_release
+    runs-on: ubuntu-latest
+    environment: *publish-environment
     permissions:
       id-token: write
       attestations: write
       # Necessary for the github token to upload artifacts to the release.
       contents: write
-    needs:
-      - create-draft-release
-      - build-win
-    secrets:
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-win.outputs.artifact_ids }}
-      artifact_platform: windows-msvc
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
+    needs: *upload-artifacts-needs
+    strategy: *upload-artifacts-strategy
+    env:
+      ARTIFACT_IDS: ${{ matrix.artifact_ids }}
+      ARTIFACT_PLATFORM: ${{ matrix.artifact_platform }}
+      GITHUB_RELEASE_ID: ${{ needs.create-draft-release.outputs.release-id }}
+      RELEASE_REPO: ${{ github.repository_owner }}/servo
+      RELEASE_REPO_TOKEN: ${{ github.token }}
+      S3_UPLOAD_CREDENTIALS: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
+    steps: *upload-artifacts-steps
 
 
   build-mac:
@@ -191,46 +281,6 @@ jobs:
       profile: "production"
       force-github-hosted-runner: true  # <https://github.com/servo/servo/issues/33296>
 
-  upload-mac-nightly:
-    # Only run scheduled nightly builds on upstream servo.
-    if: |
-      (github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch')
-        && (inputs.regular_release || false) == false
-    permissions:
-      id-token: write
-      attestations: write
-    needs:
-      - create-draft-release
-      - build-mac
-    secrets:
-      github_upload_token: ${{ secrets.NIGHTLY_REPO_TOKEN }}
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-mac.outputs.artifact_ids }}
-      artifact_platform: mac
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo:  ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
-  upload-mac-release:
-    if: github.event_name == 'workflow_dispatch' && inputs.regular_release
-    permissions:
-      id-token: write
-      attestations: write
-      # Necessary for the github token to upload artifacts to the release.
-      contents: write
-    needs:
-      - create-draft-release
-      - build-mac
-    secrets:
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-mac.outputs.artifact_ids }}
-      artifact_platform: mac
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo:  ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
   build-mac-arm64:
     # This job is only useful when run on upstream servo.
     if: github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch'
@@ -240,46 +290,6 @@ jobs:
       profile: "production"
       force-github-hosted-runner: true  # <https://github.com/servo/servo/issues/33296>
 
-  upload-mac-arm64-nightly:
-    # Only run scheduled nightly builds on upstream servo.
-    if: |
-      (github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch')
-        && (inputs.regular_release || false) == false
-    permissions:
-      id-token: write
-      attestations: write
-    needs:
-      - create-draft-release
-      - build-mac-arm64
-    secrets:
-      github_upload_token: ${{ secrets.NIGHTLY_REPO_TOKEN }}
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-mac-arm64.outputs.artifact_ids }}
-      artifact_platform: mac-arm64
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
-  upload-mac-arm64-release:
-    if: github.event_name == 'workflow_dispatch' && inputs.regular_release
-    permissions:
-      id-token: write
-      attestations: write
-      # Necessary for the github token to upload artifacts to the release.
-      contents: write
-    needs:
-      - create-draft-release
-      - build-mac-arm64
-    secrets:
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-mac-arm64.outputs.artifact_ids }}
-      artifact_platform: mac-arm64
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
   build-linux:
     # This job is only useful when run on upstream servo.
     if: github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch'
@@ -289,96 +299,15 @@ jobs:
       profile: "production"
       force-github-hosted-runner: true  # <https://github.com/servo/servo/issues/33296>
 
-  upload-linux-nightly:
-    # Only run scheduled nightly builds on upstream servo.
-    if: |
-      (github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch')
-        && (inputs.regular_release || false) == false
-    permissions:
-      id-token: write
-      attestations: write
-    needs:
-      - create-draft-release
-      - build-linux
-    secrets:
-      github_upload_token: ${{ secrets.NIGHTLY_REPO_TOKEN }}
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-linux.outputs.artifact_ids }}
-      artifact_platform: linux
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
-  upload-linux-release:
-    if: github.event_name == 'workflow_dispatch' && inputs.regular_release
-    permissions:
-      id-token: write
-      attestations: write
-      # Necessary for the github token to upload artifacts to the release.
-      contents: write
-    needs:
-      - create-draft-release
-      - build-linux
-    secrets:
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-linux.outputs.artifact_ids }}
-      artifact_platform: linux
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
   build-android:
     # This job is only useful when run on upstream servo.
     if: github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch'
     name: Build release (Android)
     uses: ./.github/workflows/android.yml
     with:
-      profile: "release"
+      profile: "production"
     secrets: inherit
 
-  upload-android-nightly:
-    # Only run scheduled nightly builds on upstream servo.
-    if: |
-      (github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch')
-        && (inputs.regular_release || false) == false
-    permissions:
-      id-token: write
-      attestations: write
-    needs:
-      - create-draft-release
-      - build-android
-    secrets:
-      github_upload_token: ${{ secrets.NIGHTLY_REPO_TOKEN }}
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-android.outputs.artifact_ids }}
-      artifact_platform: android
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
-  upload-android-release:
-    if: github.event_name == 'workflow_dispatch' && inputs.regular_release
-    permissions:
-      id-token: write
-      attestations: write
-      # Necessary for the github token to upload artifacts to the release.
-      contents: write
-    needs:
-      - create-draft-release
-      - build-android
-    secrets:
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-android.outputs.artifact_ids }}
-      artifact_platform: android
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
-
   build-ohos:
     # This job is only useful when run on upstream servo.
     if: github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch'
@@ -388,43 +317,3 @@ jobs:
       profile: "production"
       upload_library: true
     secrets: inherit
-
-  upload-ohos-nightly:
-    # Only run scheduled nightly builds on upstream servo.
-    if: |
-      (github.repository == 'servo/servo' || github.event_name == 'workflow_dispatch')
-        && (inputs.regular_release || false) == false
-    permissions:
-      id-token: write
-      attestations: write
-    needs:
-      - create-draft-release
-      - build-ohos
-    secrets:
-      github_upload_token: ${{ secrets.NIGHTLY_REPO_TOKEN }}
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-ohos.outputs.artifact_ids }}
-      artifact_platform: ohos
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}
-
-  upload-ohos-release:
-    if: github.event_name == 'workflow_dispatch' && inputs.regular_release
-    permissions:
-      id-token: write
-      attestations: write
-      # Necessary for the github token to upload artifacts to the release.
-      contents: write
-    needs:
-      - create-draft-release
-      - build-ohos
-    secrets:
-      s3_upload_token: ${{ secrets.S3_UPLOAD_CREDENTIALS }}
-    uses: ./.github/workflows/upload_release.yml
-    with:
-      artifact_ids: ${{ needs.build-ohos.outputs.artifact_ids }}
-      artifact_platform: ohos
-      github_release_id: ${{ needs.create-draft-release.outputs.release-id }}
-      target_repo: ${{ github.repository_owner }}/${{ inputs.regular_release && 'servo' || 'servo-nightly-builds' }}

.github/workflows/upload_release.yml

@@ -1,69 +0,0 @@
-name: Upload and Attest Release Assets
-on:
-  workflow_call:
-    inputs:
-      artifact_platform:
-        type: string
-        required: true
-        description: "The platform of the release artifacts to upload."
-      target_repo:
-        type: string
-        required: true
-        description: "The target repository owner and name (e.g. `servo/servo`) where the release will be created."
-      github_release_id:
-        type: string
-        required: true
-        description: "The ID of the GitHub release to which assets will be added."
-      artifact_ids:
-        required: true
-        type: string
-        description: "A comma-separated list of artifact IDs to upload."
-    secrets:
-      github_upload_token:
-        required: false
-        description: "A GitHub token with permission to upload release assets. If omitted github.token will be used instead."
-      s3_upload_token:
-        required: true
-        description: "A token with permission to upload release artifacts to our S3 bucket."
-
-
-jobs:
-  upload-artifact:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v6
-        with:
-          sparse-checkout: |
-            .github
-            etc/ci
-          fetch-depth: '1'
-      - name: Setup Python
-        uses: ./.github/actions/setup-python
-      - name: Validate artifact IDs
-        run: |
-          if [[ -z "${{ inputs.artifact_ids }}" ]]; then
-            echo "Error: No artifact IDs provided."
-            echo "Help: Check the calling workflow's output.artifact_ids parameter, usually created by a build workflow."
-            echo "If you recently renamed the build job for the artifacts, without updating the `outputs.artifact_ids` "
-            echo "parameter then this might be the cause of the error."
-            exit 1
-          fi
-      - uses: actions/download-artifact@v8
-        with:
-          artifact-ids: ${{ inputs.artifact_ids }}
-          merge-multiple: true
-          path: release-artifacts
-      - name: Generate artifact attestation
-        uses: actions/attest-build-provenance@v3
-        with:
-          subject-path: 'release-artifacts/*'
-      - name: Upload release artifacts
-        run: |
-          ./etc/ci/upload_nightly.py ${{ inputs.artifact_platform}} \
-            --secret-from-environment \
-            --github-release-id ${{ inputs.github_release_id }} \
-            release-artifacts/*
-        env:
-          S3_UPLOAD_CREDENTIALS: ${{ secrets.s3_upload_token }}
-          RELEASE_REPO_TOKEN: ${{ secrets.github_upload_token || github.token }}
-          RELEASE_REPO: ${{ inputs.target_repo }}

.github/workflows/windows.yml

@@ -157,13 +157,13 @@ jobs:
       - name: Smoketest
         run: .\mach smoketest --profile ${{ inputs.profile }}
       - name: Install cargo nextest
-        if: ${{ runner.environment != 'self-hosted' }}
+        if: ${{ runner.environment != 'self-hosted' && inputs.unit-tests }}
         uses: taiki-e/install-action@v2
         with:
           tool: nextest
       # On self-hosted windows runners the install-action fails
       - name: Install cargo nextest (self-hosted)
-        if: ${{ runner.environment == 'self-hosted' }}
+        if: ${{ runner.environment == 'self-hosted' && inputs.unit-tests }}
         run: cargo install cargo-nextest --locked
       - name: Unit tests
         if: ${{ inputs.unit-tests }}

Cargo.toml

@@ -10,7 +10,7 @@ default-members = ["ports/servoshell"]
 exclude = [".cargo", "support/crown"]
 
 [workspace.package]
-version = "0.0.6"
+version = "0.1.0"
 authors = ["The Servo Project Developers"]
 repository = "https://github.com/servo/servo"
 # A generic description for packages that don't have a meaningful description yet.
@@ -37,7 +37,7 @@ arboard = "3"
 argon2 = { version = "0.5", features = ["alloc"] }
 arrayvec = "0.7"
 async-tungstenite = { version = "0.34", features = ["tokio-rustls-webpki-roots"] }
-atomic_refcell = "0.1.13"
+atomic_refcell = "0.1.14"
 aws-lc-rs = { version = "1.16", default-features = false, features = ["aws-lc-sys"] }
 backtrace = "0.3"
 base64 = "0.22.1"
@@ -46,6 +46,8 @@ bitflags = "2.11"
 brotli = "8.0.2"
 bytemuck = "1"
 byteorder = "1.5"
+bytes = "1.0"
+byte-slice-cast = "1.2.3"
 cbc = "0.1.2"
 cfg-if = "1.0.4"
 chacha20poly1305 = "0.10"
@@ -75,7 +77,7 @@ futures-util = { version = "0.3", default-features = false }
 gleam = "0.15"
 glib = "0.22"
 glib-sys = "0.22"
-glow = "0.16.0"
+glow = "0.17.0"
 gstreamer = { version = "0.25", features = ["v1_18"] }
 gstreamer-app = "0.25"
 gstreamer-audio = "0.25"
@@ -97,7 +99,7 @@ hkdf = "0.12"
 html5ever = "0.39"
 http = "1.4"
 http-body-util = "0.1"
-hyper = "1.8"
+hyper = "1.9"
 hyper-rustls = { version = "0.27", default-features = false, features = ["http1", "http2", "logging", "tls12", "webpki-tokio"] }
 hyper-util = { version = "0.1", features = ["client-legacy", "http2", "tokio", "client-proxy"] }
 icu_locid = "1.5.0"
@@ -105,13 +107,15 @@ icu_properties = "1.5.0"
 icu_segmenter = "1.5.0"
 image = { version = "0.25", default-features = false, features = ["avif", "rayon", "bmp", "gif", "ico", "jpeg", "png", "webp"] }
 imsz = "0.4"
-indexmap = { version = "2.11.4", features = ["std"] }
+indexmap = { version = "2.14.0", features = ["std"] }
+inventory = { version = "0.3.24" }
 ipc-channel = "0.21"
 itertools = "0.14"
-js = { package = "mozjs", version = "=0.15.7", default-features = false, features = ["libz-sys", "intl"] }
+js = { package = "mozjs", version = "=0.15.9", default-features = false, features = ["libz-sys", "intl"] }
 keyboard-types = { version = "0.8.3", features = ["serde", "webdriver"] }
 kurbo = { version = "0.12", features = ["euclid"] }
 libc = "0.2"
+lru = "0.17"
 log = "0.4.29"
 mach2 = "0.6"
 malloc_size_of_derive = "0.1"
@@ -127,6 +131,7 @@ nix = "0.30"
 nom = "8.0.0"
 nom-rfc8288 = "0.4.0"
 num-bigint-dig = "0.8"
+num-complex = "0.4.6"
 num-derive = "0.4.2"
 num-traits = "0.2"
 num_cpus = "1.17.0"
@@ -147,6 +152,7 @@ postcard = { version = "1.1.3", default-features = false, features = ["use-std"]
 proc-macro2 = "1"
 quote = "1"
 rand = "0.9"
+rangemap = "1.7.1"
 raw-window-handle = "0.6"
 rayon = "1"
 read-fonts = "0.35.0"
@@ -156,33 +162,34 @@ rsa = { version = "0.9.10", features = ["sha1", "sha2"] }
 rustc-hash = "2.1.2"
 rustls = { version = "0.23", default-features = false, features = ["logging", "std", "tls12"] }
 rustls-pki-types = "1.14"
-rustls-platform-verifier = "0.6.2"
-sea-query = { version = "1.0.0-rc.31", default-features = false, features = ["backend-sqlite", "derive"] }
-sea-query-rusqlite = { version = "0.8.0-rc.15" }
+rustls-platform-verifier = "0.7.0"
+sea-query = { version = "=1.0.0-rc.31", default-features = false, features = ["backend-sqlite", "derive"] }
+sea-query-rusqlite = { version = "=0.8.0-rc.15" }
 sec1 = "0.7"
-selectors = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
+selectors = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
 serde = "1.0.228"
 serde_bytes = "0.11"
 serde_core = "1.0.226"
 serde_json = "1.0"
-servo_arc = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
+servo_arc = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
 sha1 = "0.10"
 sha2 = "0.10"
 sha3 = "0.10"
+speexdsp-resampler = "0.1.0"
 skrifa = "0.37.0"
 smallvec = { version = "1.15", features = ["serde", "union"] }
 string_cache = "0.9"
 strum = { version = "0.28", features = ["derive"] }
-stylo = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
-stylo_atoms = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
-stylo_dom = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
-stylo_malloc_size_of = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
-stylo_static_prefs = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
-stylo_traits = { git = "https://github.com/servo/stylo", rev = "938e58caf26b6d0437291ce875dd5b0dd8a52d4f" }
-surfman = { version = "0.11.0", features = ["chains"] }
+stylo = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
+stylo_atoms = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
+stylo_dom = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
+stylo_malloc_size_of = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
+stylo_static_prefs = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
+stylo_traits = { git = "https://github.com/servo/stylo", rev = "a556f4cbd15fc289039261661b049a5dc845cd80" }
+surfman = { version = "0.12.0", features = ["chains"] }
 syn = { version = "2", default-features = false, features = ["clone-impls", "derive", "parsing"] }
 synstructure = "0.13"
-taffy = { version = "0.9.2", default-features = false, features = ["calc", "detailed_layout_info", "grid", "std"] }
+taffy = { version = "0.10.1", default-features = false, features = ["calc", "detailed_layout_info", "grid", "std"] }
 tendril = { version = "0.5", features = ["encoding_rs"] }
 tikv-jemalloc-sys = "0.6.1"
 tikv-jemallocator = "0.6.1"
@@ -204,13 +211,14 @@ unicode-segmentation = "1.13.2"
 url = "2.5"
 urlpattern = "0.3"
 utf-8 = "0.7"
-uuid = { version = "1.22.0", features = ["v4", "v5"] }
+uuid = { version = "1.23.1", features = ["v4", "v5"] }
 vello = "0.6"
 vello_cpu = "0.0.4"
-webdriver = "0.53.0"
+webdriver = { version = "0.53.0", default-features = false }
 webpki-roots = "1.0"
 webrender = { version = "0.68", features = ["capture"] }
 webrender_api = "0.68"
+web_atoms = "0.2"
 wgpu-core = "26"
 wgpu-types = "26"
 winapi = "0.3"
@@ -219,8 +227,8 @@ winit = "0.30.13"
 wio = "0.2"
 wr_malloc_size_of = "0.2.2"
 x25519-dalek = { version = "2.0.1", features = ["static_secrets"] }
-xi-unicode = "0.3.0"
 xml5ever = "0.39"
+yuv = { version = "0.8.13", features = ["rayon"] }
 
 ############################################################################################
 ## Workspace-local dependencies
@@ -229,73 +237,74 @@ xml5ever = "0.39"
 # be listed here, between the `Begin` and `End` comments, so that we can easily find and
 # update the version requirements when bumping the workspace version.
 # Begin workspace-version dependencies - Don't change this comment, we grep for it in scripts!
-deny_public_fields = { package = "servo-deny-public-fields", version = "0.0.6", path = "components/deny_public_fields" }
-devtools = { package = "servo-devtools", version = "0.0.6", path = "components/devtools" }
-devtools_traits = { package = "servo-devtools-traits", version = "0.0.6", path = "components/shared/devtools" }
-dom_struct = { package = "servo-dom-struct", version = "0.0.6", path = "components/dom_struct" }
-embedder_traits = { package = "servo-embedder-traits", version = "0.0.6", path = "components/shared/embedder" }
-fonts = { package = "servo-fonts", version = "0.0.6", path = "components/fonts" }
-fonts_traits = { package = "servo-fonts-traits", version = "0.0.6", path = "components/shared/fonts" }
-jstraceable_derive = { package = "servo-jstraceable-derive", version = "0.0.6", path = "components/jstraceable_derive" }
-layout = { package = "servo-layout", version = "0.0.6", path = "components/layout" }
-layout_api = { package = "servo-layout-api", version = "0.0.6", path = "components/shared/layout" }
-malloc_size_of = { package = "servo-malloc-size-of", version = "0.0.6", path = "components/malloc_size_of" }
-media = { package = "servo-media-thread", version = "0.0.6", path = "components/media/media-thread" }
-metrics = { package = "servo-metrics", version = "0.0.6", path = "components/metrics" }
-net = { package = "servo-net", version = "0.0.6", path = "components/net" }
-net_traits = { package = "servo-net-traits", version = "0.0.6", path = "components/shared/net" }
-paint = { package = "servo-paint", version = "0.0.6", path = "components/paint" }
-paint_api = { package = "servo-paint-api", version = "0.0.6", path = "components/shared/paint" }
-pixels = { package = "servo-pixels", version = "0.0.6", path = "components/pixels" }
-profile = { package = "servo-profile", version = "0.0.6", path = "components/profile" }
-profile_traits = { package = "servo-profile-traits", version = "0.0.6", path = "components/shared/profile" }
-script = { package = "servo-script", version = "0.0.6", path = "components/script" }
-script_bindings = { package = "servo-script-bindings", version = "0.0.6", path = "components/script_bindings" }
-script_traits = { package = "servo-script-traits", version = "0.0.6", path = "components/shared/script" }
-servo = { version = "0.0.6", path = "components/servo", default-features = false }
-servo-allocator = { version = "0.0.6", path = "components/allocator" }
-servo-background-hang-monitor = { version = "0.0.6", path = "components/background_hang_monitor" }
-servo-background-hang-monitor-api = { version = "0.0.6", path = "components/shared/background_hang_monitor" }
-servo-base = { version = "0.0.6", path = "components/shared/base" }
-servo-bluetooth = { version = "0.0.6", path = "components/bluetooth" }
-servo-bluetooth-traits = { version = "0.0.6", path = "components/shared/bluetooth" }
-servo-canvas = { version = "0.0.6", path = "components/canvas" }
-servo-canvas-traits = { version = "0.0.6", path = "components/shared/canvas" }
-servo-config = { version = "0.0.6", path = "components/config" }
-servo-config-macro = { version = "0.0.6", path = "components/config/macro" }
-servo-constellation = { version = "0.0.6", path = "components/constellation" }
-servo-constellation-traits = { version = "0.0.6", path = "components/shared/constellation" }
-servo-geometry = { version = "0.0.6", path = "components/geometry" }
-servo-media = { version = "0.0.6", path = "components/media/servo-media" }
-servo-media-audio = { version = "0.0.6", path = "components/media/audio" }
-servo-media-auto = { version = "0.0.6", path = "components/media/backends/auto" }
-servo-media-derive = { version = "0.0.6", path = "components/media/servo-media-derive" }
-servo-media-dummy = { version = "0.0.6", path = "components/media/backends/dummy" }
-servo-media-gstreamer = { version = "0.0.6", path = "components/media/backends/gstreamer" }
-servo-media-gstreamer-render = { version = "0.0.6", path = "components/media/backends/gstreamer/render" }
-servo-media-gstreamer-render-android = { version = "0.0.6", path = "components/media/backends/gstreamer/render-android" }
-servo-media-gstreamer-render-unix = { version = "0.0.6", path = "components/media/backends/gstreamer/render-unix" }
-servo-media-player = { version = "0.0.6", path = "components/media/player" }
-servo-media-streams = { version = "0.0.6", path = "components/media/streams" }
-servo-media-traits = { version = "0.0.6", path = "components/media/traits" }
-servo-media-webrtc = { version = "0.0.6", path = "components/media/webrtc" }
-servo-tracing = { version = "0.0.6", path = "components/servo_tracing" }
-servo-url = { version = "0.0.6", path = "components/url" }
-storage = { package = "servo-storage", version = "0.0.6", path = "components/storage" }
-storage_traits = { package = "servo-storage-traits", version = "0.0.6", path = "components/shared/storage" }
-timers = { package = "servo-timers", version = "0.0.6", path = "components/timers" }
-webdriver_server = { package = "servo-webdriver-server", version = "0.0.6", path = "components/webdriver_server" }
-webgl = { package = "servo-webgl", version = "0.0.6", path = "components/webgl", default-features = false }
-webgpu = { package = "servo-webgpu", version = "0.0.6", path = "components/webgpu" }
-webgpu_traits = { package = "servo-webgpu-traits", version = "0.0.6", path = "components/shared/webgpu" }
-webxr = { package = "servo-webxr", version = "0.0.6", path = "components/webxr" }
-webxr-api = { package = "servo-webxr-api", version = "0.0.6", path = "components/shared/webxr" }
-xpath = { package = "servo-xpath", version = "0.0.6", path = "components/xpath" }
+deny_public_fields = { package = "servo-deny-public-fields", version = "0.1.0", path = "components/deny_public_fields" }
+devtools = { package = "servo-devtools", version = "0.1.0", path = "components/devtools" }
+devtools_traits = { package = "servo-devtools-traits", version = "0.1.0", path = "components/shared/devtools" }
+dom_struct = { package = "servo-dom-struct", version = "0.1.0", path = "components/dom_struct" }
+embedder_traits = { package = "servo-embedder-traits", version = "0.1.0", path = "components/shared/embedder" }
+fonts = { package = "servo-fonts", version = "0.1.0", path = "components/fonts" }
+fonts_traits = { package = "servo-fonts-traits", version = "0.1.0", path = "components/shared/fonts" }
+hyper_serde = { package = "servo-hyper-serde", version = "0.1.0", path = "components/hyper_serde" }
+jstraceable_derive = { package = "servo-jstraceable-derive", version = "0.1.0", path = "components/jstraceable_derive" }
+layout = { package = "servo-layout", version = "0.1.0", path = "components/layout" }
+layout_api = { package = "servo-layout-api", version = "0.1.0", path = "components/shared/layout" }
+malloc_size_of = { package = "servo-malloc-size-of", version = "0.1.0", path = "components/malloc_size_of" }
+media = { package = "servo-media-thread", version = "0.1.0", path = "components/media/media-thread" }
+metrics = { package = "servo-metrics", version = "0.1.0", path = "components/metrics" }
+net = { package = "servo-net", version = "0.1.0", path = "components/net" }
+net_traits = { package = "servo-net-traits", version = "0.1.0", path = "components/shared/net" }
+paint = { package = "servo-paint", version = "0.1.0", path = "components/paint" }
+paint_api = { package = "servo-paint-api", version = "0.1.0", path = "components/shared/paint" }
+pixels = { package = "servo-pixels", version = "0.1.0", path = "components/pixels" }
+profile = { package = "servo-profile", version = "0.1.0", path = "components/profile" }
+profile_traits = { package = "servo-profile-traits", version = "0.1.0", path = "components/shared/profile" }
+script = { package = "servo-script", version = "0.1.0", path = "components/script" }
+script_bindings = { package = "servo-script-bindings", version = "0.1.0", path = "components/script_bindings" }
+script_traits = { package = "servo-script-traits", version = "0.1.0", path = "components/shared/script" }
+servo = { version = "0.1.0", path = "components/servo", default-features = false }
+servo-allocator = { version = "0.1.0", path = "components/allocator" }
+servo-background-hang-monitor = { version = "0.1.0", path = "components/background_hang_monitor" }
+servo-background-hang-monitor-api = { version = "0.1.0", path = "components/shared/background_hang_monitor" }
+servo-base = { version = "0.1.0", path = "components/shared/base" }
+servo-bluetooth = { version = "0.1.0", path = "components/bluetooth" }
+servo-bluetooth-traits = { version = "0.1.0", path = "components/shared/bluetooth" }
+servo-canvas = { version = "0.1.0", path = "components/canvas" }
+servo-canvas-traits = { version = "0.1.0", path = "components/shared/canvas" }
+servo-config = { version = "0.1.0", path = "components/config" }
+servo-config-macro = { version = "0.1.0", path = "components/config/macro" }
+servo-constellation = { version = "0.1.0", path = "components/constellation" }
+servo-constellation-traits = { version = "0.1.0", path = "components/shared/constellation" }
+servo-default-resources = { version = "0.1.0", path = "components/default-resources" }
+servo-geometry = { version = "0.1.0", path = "components/geometry" }
+servo-media = { version = "0.1.0", path = "components/media/servo-media" }
+servo-media-audio = { version = "0.1.0", path = "components/media/audio" }
+servo-media-auto = { version = "0.1.0", path = "components/media/backends/auto" }
+servo-media-derive = { version = "0.1.0", path = "components/media/servo-media-derive" }
+servo-media-dummy = { version = "0.1.0", path = "components/media/backends/dummy" }
+servo-media-gstreamer = { version = "0.1.0", path = "components/media/backends/gstreamer" }
+servo-media-gstreamer-render = { version = "0.1.0", path = "components/media/backends/gstreamer/render" }
+servo-media-gstreamer-render-android = { version = "0.1.0", path = "components/media/backends/gstreamer/render-android" }
+servo-media-gstreamer-render-unix = { version = "0.1.0", path = "components/media/backends/gstreamer/render-unix" }
+servo-media-ohos = { version = "0.1.0", path = "components/media/backends/ohos" }
+servo-media-player = { version = "0.1.0", path = "components/media/player" }
+servo-media-streams = { version = "0.1.0", path = "components/media/streams" }
+servo-media-traits = { version = "0.1.0", path = "components/media/traits" }
+servo-media-webrtc = { version = "0.1.0", path = "components/media/webrtc" }
+servo-tracing = { version = "0.1.0", path = "components/servo_tracing" }
+servo-url = { version = "0.1.0", path = "components/url" }
+servo-wakelock = { version = "0.1.0", path = "components/wakelock" }
+storage = { package = "servo-storage", version = "0.1.0", path = "components/storage" }
+storage_traits = { package = "servo-storage-traits", version = "0.1.0", path = "components/shared/storage" }
+timers = { package = "servo-timers", version = "0.1.0", path = "components/timers" }
+webdriver_server = { package = "servo-webdriver-server", version = "0.1.0", path = "components/webdriver_server" }
+webgl = { package = "servo-webgl", version = "0.1.0", path = "components/webgl", default-features = false }
+webgpu = { package = "servo-webgpu", version = "0.1.0", path = "components/webgpu" }
+webgpu_traits = { package = "servo-webgpu-traits", version = "0.1.0", path = "components/shared/webgpu" }
+webxr = { package = "servo-webxr", version = "0.1.0", path = "components/webxr" }
+webxr-api = { package = "servo-webxr-api", version = "0.1.0", path = "components/shared/webxr" }
+xpath = { package = "servo-xpath", version = "0.1.0", path = "components/xpath" }
 # End workspace-version dependencies - Don't change this comment, we grep for it in scripts!
 
-# Independently versioned workspace local crates. These crates will not take part in auto-bumps.
-hyper_serde = { package = "servo-hyper-serde", version = "0.13.2", path = "components/hyper_serde" }
-
 # RSA key generation could be very slow without compilation
 # optimizations, in development mode. Without optimizations, WPT might
 # consider RSA key generation tests fail due to timeout.
@@ -361,7 +370,7 @@ codegen-units = 1
 # web_atoms = { path = "../html5ever/web_atoms" }
 # xml5ever = { path = "../html5ever/xml5ever" }
 # tendril = { path = "../html5ever/tendril" }
-
+#
 # For WebRender:
 #
 # webrender = { path = "../webrender/webrender" }
@@ -376,12 +385,6 @@ codegen-units = 1
 # Or for CSP crate:
 # content-security-policy = { path = "../rust-content-security-policy" }
 #
-# Pending egui bumping their accesskit version: https://github.com/emilk/egui/pull/7850
-# This is only used in servoshell.
-# TODO: When these are no longer needed remove the exception in deny.toml as well.
-egui = { git = "https://github.com/emilk/egui.git", rev = "5d8f393335e051785b4fd3af9ef92eda5b61177f" }
-egui-winit = { git = "https://github.com/emilk/egui.git", rev = "5d8f393335e051785b4fd3af9ef92eda5b61177f" }
-#
 # Or for Stylo:
 #
 # [patch."https://github.com/servo/stylo"]

PULL_REQUEST_TEMPLATE.md

@@ -1,4 +1,5 @@
-*Describe the changes that this pull request makes here. This will be the commit message.*
+*Describe the changes that this pull request makes here. This will be the commit message
+and it should go at the top of the pull request.*
 
-Testing: *Describe how this pull request is tested or why it doesn't require tests*
-Fixes: *Link to an issue this pull requests fixes or remove this line if there is no issue*
+Testing: *Describe the new automated tests that cover this change or explain why it doesn't require tests.*
+Fixes: *Link to an issue this pull request fixes or remove this line if there is no issue.*

components/background_hang_monitor/lib.rs

@@ -37,6 +37,7 @@ pub use self::background_hang_monitor::*;
         )
     ),
     all(target_os = "windows", target_arch = "aarch64"),
+    target_os = "freebsd"
 ))]
 pub(crate) use crate::sampler::DummySampler as SamplerImpl;
 #[cfg(all(

components/canvas/canvas_data.rs

@@ -318,7 +318,7 @@ impl<DrawTarget: GenericDrawTarget> CanvasData<DrawTarget> {
 
         let (descriptor, data) = {
             let _span =
-                profile_traits::trace_span!("image_descriptor_and_serializable_data",).entered();
+                profile_traits::trace_span!("image_descriptor_and_serializable_data").entered();
             self.draw_target.image_descriptor_and_serializable_data()
         };
 

components/config/lib.rs

@@ -2,6 +2,12 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+//! This crate provides two mechanisms for configuring the behaviour of the Servo engine.
+//!  - The [`opts`] module exposes a set of global flags that are initialized once
+//!    and cannot be changed at runtime.
+//!  - The [`prefs`] module provides a mechanism to get and set global preference
+//!    values that can be changed at runtime.
+
 #![deny(unsafe_code)]
 
 pub mod opts;

components/config/opts.rs

@@ -2,8 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-//! Configuration options for a single run of the servo application. Created
-//! from command line arguments.
+//! Options are global configuration options that are initialized once and cannot be changed at
+//! runtime.
 
 use std::default::Default;
 use std::path::PathBuf;
@@ -12,15 +12,14 @@ use std::sync::OnceLock;
 
 use serde::{Deserialize, Serialize};
 
-/// Global flags for Servo, currently set on the command line.
+/// The set of global options supported by Servo. The values for these can be configured during
+/// initialization of Servo and cannot be changed later at runtime.
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct Opts {
-    /// `None` to disable the time profiler or `Some` to enable it with:
+    /// `None` to disable the time profiler or `Some` to enable it with either:
     ///
     ///  - an interval in seconds to cause it to produce output on that interval.
-    ///    (`i.e. -p 5`).
     ///  - a file path to write profiling info to a TSV file upon Servo's termination.
-    ///    (`i.e. -p out.tsv`).
     pub time_profiling: Option<OutputOptions>,
 
     /// When the profiler is enabled, this is an optional path to dump a self-contained HTML file
@@ -79,10 +78,10 @@ pub struct Opts {
     pub unminify_css: bool,
 }
 
-/// Debug options for Servo, currently set on the command line with -Z
+/// Debug options for Servo.
 #[derive(Clone, Debug, Default, Deserialize, Serialize)]
 pub struct DiagnosticsLogging {
-    /// List all the debug options.
+    /// Print all the debug options supported by Servo to the standard output.
     pub help: bool,
 
     /// Print the DOM after each restyle.
@@ -202,9 +201,9 @@ impl DiagnosticsLogging {
     }
 }
 
+/// The destination for the time profiler reports.
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 pub enum OutputOptions {
-    /// Database connection config (hostname, name, user, pass)
     FileName(String),
     Stdout(f64),
 }
@@ -241,16 +240,16 @@ static OPTIONS: OnceLock<Opts> = OnceLock::new();
 /// Initialize options.
 ///
 /// Should only be called once at process startup.
-/// Must be called before the first call to [get].
+/// Must be called before the first call to [`get`].
 pub fn initialize_options(opts: Opts) {
     OPTIONS.set(opts).expect("Already initialized");
 }
 
 /// Get the servo options
 ///
-/// If the servo options have not been initialized by calling [initialize_options], then the
-/// options will be initialized to default values. Outside of tests the options should
-/// be explicitly initialized.
+/// If the servo options have not been initialized by calling [`initialize_options`], then the
+/// options will be initialized to default values. Outside of tests the options should be
+/// explicitly initialized.
 #[inline]
 pub fn get() -> &'static Opts {
     // In unit-tests using default options reduces boilerplate.

components/config/pref_util.rs

@@ -5,6 +5,7 @@
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
+/// The types of preference values in Servo.
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 pub enum PrefValue {
     Float(f64),
@@ -16,6 +17,8 @@ pub enum PrefValue {
 }
 
 impl PrefValue {
+    /// Parse the `input` string as a preference value. Defaults to a `PrefValue::Str` if the input
+    /// cannot be parsed as valid value of one of the other types.
     pub fn from_booleanish_str(input: &str) -> Self {
         match input {
             "false" => PrefValue::Bool(false),
@@ -95,11 +98,23 @@ impl_pref_from! {
 impl_from_pref! {
     PrefValue::Float => f64,
     PrefValue::Int => i64,
-    PrefValue::UInt => u64,
     PrefValue::Str => String,
     PrefValue::Bool => bool,
 }
 
+// The default generated from `impl_from_pref` would cause panic
+// when converting from PrefValue::Int.
+impl TryFrom<PrefValue> for u64 {
+    type Error = String;
+    fn try_from(other: PrefValue) -> Result<Self, Self::Error> {
+        match other {
+            PrefValue::UInt(value) => Ok(value),
+            PrefValue::Int(value) if value >= 0 => Ok(value as u64),
+            _ => Err(format!("Cannot convert {other:?} to u64")),
+        }
+    }
+}
+
 impl From<[f64; 4]> for PrefValue {
     fn from(other: [f64; 4]) -> PrefValue {
         PrefValue::Array(IntoIterator::into_iter(other).map(|v| v.into()).collect())

components/config/prefs.rs

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+//! Preferences are the global configuration options that can be changed at runtime.
+
 use std::env::consts::ARCH;
 use std::sync::{RwLock, RwLockReadGuard};
 use std::time::Duration;
@@ -13,7 +15,12 @@ pub use crate::pref_util::PrefValue;
 
 static PREFERENCES: RwLock<Preferences> = RwLock::new(Preferences::const_default());
 
+/// A trait to be implemented by components that wish to be notified about runtime changes to the
+/// global preferences for the current process.
 pub trait PreferencesObserver: Send + Sync {
+    /// This method is called when the global preferences have been updated. The argument to the
+    /// method is an array of tuples where the first component is the name of the preference and
+    /// the second component is the new value of the preference.
     fn prefs_changed(&self, _changes: &[(&'static str, PrefValue)]) {}
 }
 
@@ -25,10 +32,13 @@ pub fn get() -> RwLockReadGuard<'static, Preferences> {
     PREFERENCES.read().unwrap()
 }
 
+/// Subscribe to notifications about changes to the global preferences for the current process.
 pub fn add_observer(observer: Box<dyn PreferencesObserver>) {
     OBSERVERS.write().unwrap().push(observer);
 }
 
+/// Update the values of the global preferences for the current process. This also notifies the
+/// observers previously added using [`add_observer`].
 pub fn set(preferences: Preferences) {
     // Map between Stylo preference names and Servo preference names as the This should be
     // kept in sync with components/script/dom/bindings/codegen/run.py which generates the
@@ -72,6 +82,16 @@ macro_rules! pref {
     };
 }
 
+/// The set of global preferences supported by Servo.
+///
+/// Each preference has a default value that determines its initial state. These defaults
+/// fall into roughly three categories:
+/// - **Stable**: enabled by default.
+/// - **Experimental**: disabled by default, but intended to be enabled for experimental use.
+/// - **Unstable**: disabled by default.
+///
+/// For a full overview of which preferences are experimental, see the
+/// [experimental features documentation](https://book.servo.org/design-documentation/experimental-features.html).
 #[derive(Clone, Deserialize, Serialize, ServoPreferences)]
 pub struct Preferences {
     pub fonts_default: String,
@@ -131,6 +151,8 @@ pub struct Preferences {
     pub dom_gamepad_enabled: bool,
     // feature: Geolocation API | #38903 | Web/API/Geolocation_API
     pub dom_geolocation_enabled: bool,
+    // feature: Screen Wake Lock API | #43615 | Web/API/Screen_Wake_Lock_API
+    pub dom_wakelock_enabled: bool,
     // feature: IndexedDB | #6963 | Web/API/IndexedDB_API
     pub dom_indexeddb_enabled: bool,
     // feature: IntersectionObserver | #35767 | Web/API/Intersection_Observer_API
@@ -151,10 +173,16 @@ pub struct Preferences {
     pub dom_permissions_testing_allowed_in_nonsecure_contexts: bool,
     // feature: ResizeObserver | #39790 | Web/API/ResizeObserver
     pub dom_resize_observer_enabled: bool,
+    // feature: Sanitizer API | #43948 | Web/API/HTML_Sanitizer_API
+    pub dom_sanitizer_enabled: bool,
     pub dom_script_asynch: bool,
+    // feature: Storage API | #43976 | Web/API/Storage_API
+    pub dom_storage_manager_api_enabled: bool,
     // feature: ServiceWorker | #36538 | Web/API/Service_Worker_API
     pub dom_serviceworker_enabled: bool,
     pub dom_serviceworker_timeout_seconds: i64,
+    // feature: SharedWorker | #7458 | Web/API/SharedWorker
+    pub dom_sharedworker_enabled: bool,
     pub dom_servo_helpers_enabled: bool,
     pub dom_servoparser_async_html_tokenizer_enabled: bool,
     pub dom_testbinding_enabled: bool,
@@ -353,6 +381,7 @@ impl Preferences {
             dom_fullscreen_test: false,
             dom_gamepad_enabled: true,
             dom_geolocation_enabled: false,
+            dom_wakelock_enabled: false,
             dom_indexeddb_enabled: false,
             dom_intersection_observer_enabled: false,
             dom_microdata_testing_enabled: false,
@@ -365,9 +394,12 @@ impl Preferences {
             dom_permissions_enabled: false,
             dom_permissions_testing_allowed_in_nonsecure_contexts: false,
             dom_resize_observer_enabled: true,
+            dom_sanitizer_enabled: false,
             dom_script_asynch: true,
+            dom_storage_manager_api_enabled: false,
             dom_serviceworker_enabled: false,
             dom_serviceworker_timeout_seconds: 60,
+            dom_sharedworker_enabled: false,
             dom_servo_helpers_enabled: false,
             dom_servoparser_async_html_tokenizer_enabled: false,
             dom_testbinding_enabled: false,

components/constellation/Cargo.toml

@@ -19,7 +19,7 @@ bluetooth = ["servo-bluetooth-traits"]
 gamepad = ["embedder_traits/gamepad"]
 tracing = ["dep:tracing", "servo-canvas/tracing"]
 vello = ["servo-canvas/vello"]
-webgpu = ["script_traits/webgpu"]
+webgpu = ["dep:webgpu", "dep:webgpu_traits", "script_traits/webgpu"]
 
 [lints.clippy]
 unwrap_used = "deny"
@@ -28,6 +28,7 @@ panic = "deny"
 [dependencies]
 accesskit = { workspace = true }
 backtrace = { workspace = true }
+base64 = { workspace = true }
 content-security-policy = { workspace = true }
 crossbeam-channel = { workspace = true }
 devtools_traits = { workspace = true }
@@ -58,12 +59,13 @@ servo-config = { workspace = true }
 servo-constellation-traits = { workspace = true }
 servo-tracing = { workspace = true }
 servo-url = { workspace = true }
+servo-wakelock = { workspace = true }
 storage_traits = { workspace = true }
 stylo = { workspace = true }
 stylo_traits = { workspace = true }
 tracing = { workspace = true, optional = true }
-webgpu = { workspace = true }
-webgpu_traits = { workspace = true }
+webgpu = { workspace = true, optional = true }
+webgpu_traits = { workspace = true, optional = true }
 webxr-api = { workspace = true }
 
 [target.'cfg(any(target_os="macos", all(not(target_os = "windows"), not(target_os = "ios"), not(target_os="android"), not(target_env="ohos"), not(target_arch="arm"), not(target_arch="aarch64"))))'.dependencies]

components/constellation/constellation.rs

@@ -145,7 +145,8 @@ use servo_base::generic_channel::{
     GenericCallback, GenericSend, GenericSender, RoutedReceiver, SendError,
 };
 use servo_base::id::{
-    BrowsingContextGroupId, BrowsingContextId, HistoryStateId, MessagePortId, MessagePortRouterId,
+    BrowsingContextGroupId, BrowsingContextId, CONSTELLATION_PIPELINE_NAMESPACE_ID,
+    FIRST_CONTENT_PIPELINE_NAMESPACE_ID, HistoryStateId, MessagePortId, MessagePortRouterId,
     PainterId, PipelineId, PipelineNamespace, PipelineNamespaceId, PipelineNamespaceRequest,
     ScriptEventLoopId, WebViewId,
 };
@@ -158,14 +159,16 @@ use servo_canvas_traits::canvas::{CanvasId, CanvasMsg};
 use servo_canvas_traits::webgl::WebGLThreads;
 use servo_config::{opts, pref};
 use servo_constellation_traits::{
-    AuxiliaryWebViewCreationRequest, AuxiliaryWebViewCreationResponse, DocumentState,
-    EmbedderToConstellationMessage, IFrameLoadInfo, IFrameLoadInfoWithData, IFrameSizeMsg, Job,
-    LoadData, LogEntry, MessagePortMsg, NavigationHistoryBehavior, PaintMetricEvent,
-    PortMessageTask, PortTransferInfo, SWManagerMsg, SWManagerSenders, ScreenshotReadinessResponse,
-    ScriptToConstellationMessage, ScrollStateUpdate, ServiceWorkerManagerFactory, ServiceWorkerMsg,
-    StructuredSerializedData, TraversalDirection, UserContentManagerAction, WindowSizeType,
+    AuxiliaryWebViewCreationRequest, AuxiliaryWebViewCreationResponse, ConstellationInterest,
+    DocumentState, EmbedderToConstellationMessage, IFrameLoadInfo, IFrameLoadInfoWithData,
+    IFrameSizeMsg, Job, LoadData, LogEntry, MessagePortMsg, NavigationHistoryBehavior,
+    PaintMetricEvent, PortMessageTask, PortTransferInfo, SWManagerMsg, SWManagerSenders,
+    ScreenshotReadinessResponse, ScriptToConstellationMessage, ScrollStateUpdate,
+    ServiceWorkerManagerFactory, ServiceWorkerMsg, StructuredSerializedData, TargetSnapshotParams,
+    TraversalDirection, UserContentManagerAction, WindowSizeType,
 };
 use servo_url::{Host, ImmutableOrigin, ServoUrl};
+use servo_wakelock::{WakeLockProvider, WakeLockType};
 use storage_traits::StorageThreads;
 use storage_traits::client_storage::ClientStorageThreadMessage;
 use storage_traits::indexeddb::{IndexedDBThreadMsg, SyncOperation};
@@ -189,7 +192,13 @@ use crate::process_manager::ProcessManager;
 use crate::serviceworker::ServiceWorkerUnprivilegedContent;
 use crate::session_history::{NeedsToReload, SessionHistoryChange, SessionHistoryDiff};
 
-type PendingApprovalNavigations = FxHashMap<PipelineId, (LoadData, NavigationHistoryBehavior)>;
+struct PendingApprovalNavigation {
+    load_data: LoadData,
+    history_behaviour: NavigationHistoryBehavior,
+    target_snapshot_params: TargetSnapshotParams,
+}
+
+type PendingApprovalNavigations = FxHashMap<PipelineId, PendingApprovalNavigation>;
 
 #[derive(Debug)]
 /// The state used by MessagePortInfo to represent the various states the port can be in.
@@ -405,6 +414,9 @@ pub struct Constellation<STF, SWF> {
     /// Bookkeeping for BroadcastChannel functionnality.
     broadcast_channels: BroadcastChannels,
 
+    /// Tracks which pipelines have registered interest in each notification category.
+    pipeline_interests: FxHashMap<ConstellationInterest, FxHashSet<PipelineId>>,
+
     /// The set of all the pipelines in the browser.  (See the `pipeline` module
     /// for more details.)
     pipelines: FxHashMap<PipelineId, Pipeline>,
@@ -476,6 +488,13 @@ pub struct Constellation<STF, SWF> {
     /// Pipeline ID of the active media session.
     active_media_session: Option<PipelineId>,
 
+    /// Aggregate screen wake lock count across all webviews. The provider is notified
+    /// only when this transitions 0→1 (acquire) or N→0 (release).
+    screen_wake_lock_count: u32,
+
+    /// Provider for OS-level screen wake lock acquisition and release.
+    wake_lock_provider: Box<dyn WakeLockProvider>,
+
     /// The image bytes associated with the BrokenImageIcon embedder resource.
     /// Read during startup and provided to image caches that are created
     /// on an as-needed basis, rather than retrieving it every time.
@@ -573,6 +592,9 @@ pub struct InitialConstellationState {
 
     /// The async runtime.
     pub async_runtime: Box<dyn AsyncRuntime>,
+
+    /// The wake lock provider for acquiring and releasing OS-level screen wake locks.
+    pub wake_lock_provider: Box<dyn WakeLockProvider>,
 }
 
 /// When we are exiting a pipeline, we can either force exiting or not. A normal exit
@@ -651,8 +673,7 @@ where
 
                 let swmanager_receiver = swmanager_ipc_receiver.route_preserving_errors();
 
-                // Zero is reserved for the embedder.
-                PipelineNamespace::install(PipelineNamespaceId(1));
+                PipelineNamespace::install(CONSTELLATION_PIPELINE_NAMESPACE_ID);
 
                 #[cfg(feature = "webgpu")]
                 let webrender_wgpu = WebRenderWGPU {
@@ -696,12 +717,11 @@ where
                     message_ports: Default::default(),
                     message_port_routers: Default::default(),
                     broadcast_channels: Default::default(),
+                    pipeline_interests: Default::default(),
                     pipelines: Default::default(),
                     browsing_contexts: Default::default(),
                     pending_changes: vec![],
-                    // We initialize the namespace at 2, since we reserved
-                    // namespace 0 for the embedder, and 0 for the constellation
-                    next_pipeline_namespace_id: Cell::new(PipelineNamespaceId(2)),
+                    next_pipeline_namespace_id: Cell::new(FIRST_CONTENT_PIPELINE_NAMESPACE_ID),
                     time_profiler_chan: state.time_profiler_chan,
                     mem_profiler_chan: state.mem_profiler_chan.clone(),
                     phantom: PhantomData,
@@ -726,6 +746,8 @@ where
                     active_keyboard_modifiers: Modifiers::empty(),
                     hard_fail,
                     active_media_session: None,
+                    screen_wake_lock_count: 0,
+                    wake_lock_provider: state.wake_lock_provider,
                     broken_image_icon_data: broken_image_icon_data.clone(),
                     process_manager: ProcessManager::new(state.mem_profiler_chan),
                     async_runtime: state.async_runtime,
@@ -853,16 +875,11 @@ where
             },
             None => self
                 .browsing_context_group_set
-                .iter()
-                .filter_map(|(_, bc_group)| {
-                    if bc_group
+                .values()
+                .filter(|bc_group| {
+                    bc_group
                         .top_level_browsing_context_set
                         .contains(webview_id)
-                    {
-                        Some(bc_group)
-                    } else {
-                        None
-                    }
                 })
                 .last()
                 .ok_or(
@@ -1023,6 +1040,7 @@ where
         load_data: LoadData,
         is_private: bool,
         throttled: bool,
+        target_snapshot_params: TargetSnapshotParams,
     ) {
         if self.shutting_down {
             return;
@@ -1064,6 +1082,7 @@ where
             viewport_details: initial_viewport_details,
             user_content_manager_id,
             theme,
+            target_snapshot_params,
         };
         let pipeline = match Pipeline::spawn(new_pipeline_info, event_loop, self, throttled) {
             Ok(pipeline) => pipeline,
@@ -1157,7 +1176,7 @@ where
         inherited_secure_context: Option<bool>,
         throttled: bool,
     ) {
-        debug!("{}: Creating new browsing context", browsing_context_id);
+        debug!("{browsing_context_id}: Creating new browsing context");
         let bc_group_id = match self
             .browsing_context_group_set
             .iter_mut()
@@ -1253,10 +1272,12 @@ where
         self.process_manager.register(&mut sel);
 
         let request = {
-            let oper = sel.select();
+            let oper = {
+                let _span = profile_traits::trace_span!("handle_request::select").entered();
+                sel.select()
+            };
             let index = oper.index();
 
-            let _span = profile_traits::trace_span!("handle_request::select").entered();
             match index {
                 0 => oper
                     .recv(&self.namespace_receiver)
@@ -1330,6 +1351,7 @@ where
         }
     }
 
+    #[servo_tracing::instrument(skip_all)]
     fn handle_request_from_swmanager(&mut self, message: SWManagerMsg) {
         match message {
             SWManagerMsg::PostMessageToClient => {
@@ -1358,9 +1380,15 @@ where
                 };
 
                 match pending {
-                    Some((load_data, history_handling)) => {
+                    Some(pending) => {
                         if allowed {
-                            self.load_url(webview_id, pipeline_id, load_data, history_handling);
+                            self.load_url(
+                                webview_id,
+                                pipeline_id,
+                                pending.load_data,
+                                pending.history_behaviour,
+                                pending.target_snapshot_params,
+                            );
                         } else {
                             if let Some((sender, id)) = &self.webdriver_load_status_sender {
                                 if pipeline_id == *id {
@@ -1395,8 +1423,13 @@ where
             // Load a new page from a typed url
             // If there is already a pending page (self.pending_changes), it will not be overridden;
             // However, if the id is not encompassed by another change, it will be.
-            EmbedderToConstellationMessage::LoadUrl(webview_id, url) => {
-                let load_data = LoadData::new_for_new_unrelated_webview(url);
+            EmbedderToConstellationMessage::LoadUrl(webview_id, url_request) => {
+                let mut load_data = LoadData::new_for_new_unrelated_webview(url_request.url);
+
+                if !url_request.headers.is_empty() {
+                    load_data.headers.extend(url_request.headers);
+                }
+
                 let ctx_id = BrowsingContextId::from(webview_id);
                 let pipeline_id = match self.browsing_contexts.get(&ctx_id) {
                     Some(ctx) => ctx.pipeline_id,
@@ -1411,6 +1444,7 @@ where
                     pipeline_id,
                     load_data,
                     NavigationHistoryBehavior::Push,
+                    TargetSnapshotParams::default(),
                 );
             },
             // Create a new top level browsing context. Will use response_chan to return
@@ -1822,12 +1856,17 @@ where
                 self.handle_change_running_animations_state(source_pipeline_id, animation_state)
             },
             // Ask the embedder for permission to load a new page.
-            ScriptToConstellationMessage::LoadUrl(load_data, history_handling) => {
+            ScriptToConstellationMessage::LoadUrl(
+                load_data,
+                history_handling,
+                target_snapshot_params,
+            ) => {
                 self.schedule_navigation(
                     webview_id,
                     source_pipeline_id,
                     load_data,
                     history_handling,
+                    target_snapshot_params,
                 );
             },
             ScriptToConstellationMessage::AbortLoadUrl => {
@@ -1884,15 +1923,20 @@ where
                     data,
                 );
             },
-            ScriptToConstellationMessage::Focus(focused_child_browsing_context_id, sequence) => {
-                self.handle_focus_msg(
+            ScriptToConstellationMessage::FocusAncestorBrowsingContextsForFocusingSteps(
+                focused_child_browsing_context_id,
+                sequence,
+            ) => {
+                self.handle_focus_ancestor_browsing_contexts_for_focusing_steps(
                     source_pipeline_id,
                     focused_child_browsing_context_id,
                     sequence,
                 );
             },
-            ScriptToConstellationMessage::FocusRemoteDocument(focused_browsing_context_id) => {
-                self.handle_focus_remote_document_msg(focused_browsing_context_id);
+            ScriptToConstellationMessage::FocusRemoteBrowsingContext(
+                focused_browsing_context_id,
+            ) => {
+                self.handle_focus_remote_browsing_context(focused_browsing_context_id);
             },
             ScriptToConstellationMessage::SetThrottledComplete(throttled) => {
                 self.handle_set_throttled_complete(source_pipeline_id, throttled);
@@ -1975,6 +2019,20 @@ where
                     warn!("Unable to forward DOMMessage for postMessage call");
                 }
             },
+            ScriptToConstellationMessage::RegisterInterest(interest) => {
+                self.pipeline_interests
+                    .entry(interest)
+                    .or_default()
+                    .insert(source_pipeline_id);
+            },
+            ScriptToConstellationMessage::UnregisterInterest(interest) => {
+                if let Some(set) = self.pipeline_interests.get_mut(&interest) {
+                    set.remove(&source_pipeline_id);
+                    if set.is_empty() {
+                        self.pipeline_interests.remove(&interest);
+                    }
+                }
+            },
             ScriptToConstellationMessage::BroadcastStorageEvent(
                 storage,
                 url,
@@ -2065,6 +2123,26 @@ where
                     let _ = event_loop.send(ScriptThreadMessage::TriggerGarbageCollection);
                 }
             },
+            ScriptToConstellationMessage::AcquireWakeLock(type_) => match type_ {
+                WakeLockType::Screen => {
+                    self.screen_wake_lock_count += 1;
+                    if self.screen_wake_lock_count == 1 {
+                        if let Err(e) = self.wake_lock_provider.acquire(type_) {
+                            warn!("Failed to acquire screen wake lock: {e}");
+                        }
+                    }
+                },
+            },
+            ScriptToConstellationMessage::ReleaseWakeLock(type_) => match type_ {
+                WakeLockType::Screen => {
+                    self.screen_wake_lock_count = self.screen_wake_lock_count.saturating_sub(1);
+                    if self.screen_wake_lock_count == 0 {
+                        if let Err(e) = self.wake_lock_provider.release(type_) {
+                            warn!("Failed to release screen wake lock: {e}");
+                        }
+                    }
+                },
+            },
         }
     }
 
@@ -2589,7 +2667,17 @@ where
             );
         }
 
-        for pipeline in self.pipelines.values() {
+        let interested = match self
+            .pipeline_interests
+            .get(&ConstellationInterest::StorageEvent)
+        {
+            Some(set) => set,
+            None => return,
+        }
+        .iter()
+        .filter_map(|interested_id| self.pipelines.get(interested_id));
+
+        for pipeline in interested {
             if pipeline.id == pipeline_id || pipeline.url.origin() != origin {
                 continue;
             }
@@ -2897,6 +2985,12 @@ where
             return;
         };
 
+        // Clean up any registered interests for this pipeline.
+        self.pipeline_interests.retain(|_, set| {
+            set.remove(&pipeline_id);
+            !set.is_empty()
+        });
+
         // Now that the Script and Constellation parts of Servo no longer have a reference to
         // this pipeline, tell `Paint` that it has shut down. This is delayed until the
         // last moment.
@@ -3019,6 +3113,7 @@ where
             new_load_data,
             is_private,
             throttled,
+            TargetSnapshotParams::default(),
         );
         self.add_pending_change(SessionHistoryChange {
             webview_id,
@@ -3130,23 +3225,19 @@ where
         };
 
         webview.accessibility_active = active;
-        self.constellation_to_embedder_proxy.send(
-            ConstellationToEmbedderMsg::AccessibilityTreeIdChanged(
-                webview_id,
-                webview.active_top_level_pipeline_id.into(),
-            ),
+        let Some(pipeline_id) = webview.active_top_level_pipeline_id else {
+            return;
+        };
+        let epoch = webview.active_top_level_pipeline_epoch;
+        // Forward the activation to the webview’s active top-level pipeline, if any. For inactive
+        // pipelines (documents in bfcache), we only need to forward the activation if and when they
+        // become active (see set_frame_tree_for_webview()).
+        // There are two sites like this; this is the a11y activation site.
+        self.send_message_to_pipeline(
+            pipeline_id,
+            ScriptThreadMessage::SetAccessibilityActive(pipeline_id, active, epoch),
+            "Set accessibility active after closure",
         );
-
-        // Forward the activation to the webview’s active pipelines (of those that represent
-        // documents). For inactive pipelines (documents in bfcache), we only need to forward the
-        // activation if and when they become active (see set_frame_tree_for_webview()).
-        for pipeline_id in self.active_pipelines_for_webview(webview_id) {
-            self.send_message_to_pipeline(
-                pipeline_id,
-                ScriptThreadMessage::SetAccessibilityActive(pipeline_id, active),
-                "Set accessibility active after closure",
-            );
-        }
     }
 
     fn forward_input_event(
@@ -3223,13 +3314,7 @@ where
         // its focused browsing context to be itself.
         self.webviews.insert(
             webview_id,
-            ConstellationWebView::new(
-                &self.constellation_to_embedder_proxy,
-                webview_id,
-                pipeline_id,
-                browsing_context_id,
-                user_content_manager_id,
-            ),
+            ConstellationWebView::new(webview_id, browsing_context_id, user_content_manager_id),
         );
 
         // https://html.spec.whatwg.org/multipage/#creating-a-new-browsing-context-group
@@ -3251,6 +3336,7 @@ where
             load_data,
             is_private,
             throttled,
+            TargetSnapshotParams::default(),
         );
         self.add_pending_change(SessionHistoryChange {
             webview_id,
@@ -3390,6 +3476,7 @@ where
             new_pipeline_id,
             is_private,
             mut history_handling,
+            target_snapshot_params,
             ..
         } = load_info.info;
 
@@ -3469,6 +3556,7 @@ where
             load_info.load_data,
             is_private,
             browsing_context_throttled,
+            target_snapshot_params,
         );
         self.add_pending_change(SessionHistoryChange {
             webview_id,
@@ -3616,9 +3704,7 @@ where
         self.webviews.insert(
             new_webview_id,
             ConstellationWebView::new(
-                &self.constellation_to_embedder_proxy,
                 new_webview_id,
-                new_pipeline_id,
                 new_browsing_context_id,
                 user_content_manager_id,
             ),
@@ -3732,6 +3818,7 @@ where
         source_id: PipelineId,
         load_data: LoadData,
         history_handling: NavigationHistoryBehavior,
+        target_snapshot_params: TargetSnapshotParams,
     ) {
         match self.pending_approval_navigations.entry(source_id) {
             Entry::Occupied(_) => {
@@ -3741,7 +3828,11 @@ where
                 );
             },
             Entry::Vacant(entry) => {
-                let _ = entry.insert((load_data.clone(), history_handling));
+                let _ = entry.insert(PendingApprovalNavigation {
+                    load_data: load_data.clone(),
+                    history_behaviour: history_handling,
+                    target_snapshot_params,
+                });
             },
         };
         // Allow the embedder to handle the url itself
@@ -3761,6 +3852,7 @@ where
         source_id: PipelineId,
         load_data: LoadData,
         history_handling: NavigationHistoryBehavior,
+        target_snapshot_params: TargetSnapshotParams,
     ) -> Option<PipelineId> {
         debug!(
             "{}: Loading ({}replacing): {}",
@@ -3823,6 +3915,7 @@ where
                     browsing_context_id,
                     load_data,
                     history_handling,
+                    target_snapshot_params,
                 );
                 let result = match self.pipelines.get(&parent_pipeline_id) {
                     Some(parent_pipeline) => parent_pipeline.event_loop.send(msg),
@@ -3880,6 +3973,7 @@ where
                     load_data,
                     is_private,
                     is_throttled,
+                    target_snapshot_params,
                 );
                 self.add_pending_change(SessionHistoryChange {
                     webview_id,
@@ -4174,6 +4268,10 @@ where
                     load_data.clone(),
                     is_private,
                     throttled,
+                    // TODO(jdm): We need to store the original target snapshot params
+                    // with the pipeline when it's created, so we can support reloading
+                    // a discarded document properly.
+                    TargetSnapshotParams::default(),
                 );
                 self.add_pending_change(SessionHistoryChange {
                     webview_id,
@@ -4413,7 +4511,7 @@ where
     }
 
     #[servo_tracing::instrument(skip_all)]
-    fn handle_focus_msg(
+    fn handle_focus_ancestor_browsing_contexts_for_focusing_steps(
         &mut self,
         pipeline_id: PipelineId,
         focused_child_browsing_context_id: Option<BrowsingContextId>,
@@ -4453,23 +4551,20 @@ where
         self.focus_browsing_context(Some(pipeline_id), focused_browsing_context_id);
     }
 
-    fn handle_focus_remote_document_msg(&mut self, focused_browsing_context_id: BrowsingContextId) {
-        let pipeline_id = match self.browsing_contexts.get(&focused_browsing_context_id) {
-            Some(browsing_context) => browsing_context.pipeline_id,
-            None => return warn!("Browsing context {} not found", focused_browsing_context_id),
+    fn handle_focus_remote_browsing_context(&mut self, target: BrowsingContextId) {
+        let Some(browsing_context) = self.browsing_contexts.get(&target) else {
+            return warn!("{target:?} not found for focus message");
         };
-
-        // Ignore if its active document isn't fully active.
-        if self.get_activity(pipeline_id) != DocumentActivity::FullyActive {
-            debug!(
-                "Ignoring the remote focus request because pipeline {} of \
-                browsing context {} is not fully active",
-                pipeline_id, focused_browsing_context_id,
-            );
-            return;
+        let pipeline_id = browsing_context.pipeline_id;
+        let Some(pipeline) = self.pipelines.get(&pipeline_id) else {
+            return warn!("{pipeline_id:?} not found for focus message");
+        };
+        if let Err(error) = pipeline
+            .event_loop
+            .send(ScriptThreadMessage::FocusDocument(pipeline_id))
+        {
+            self.handle_send_error(pipeline_id, error);
         }
-
-        self.focus_browsing_context(None, focused_browsing_context_id);
     }
 
     /// Perform [the focusing steps][1] for the active document of
@@ -4570,7 +4665,10 @@ where
         // > substeps: [...]
         for &pipeline in old_focus_chain_pipelines.iter() {
             if Some(pipeline.id) != initiator_pipeline_id {
-                let msg = ScriptThreadMessage::Unfocus(pipeline.id, pipeline.focus_sequence);
+                let msg = ScriptThreadMessage::UnfocusDocumentAsPartOfFocusingSteps(
+                    pipeline.id,
+                    pipeline.focus_sequence,
+                );
                 trace!("Sending {:?} to {}", msg, pipeline.id);
                 if let Err(e) = pipeline.event_loop.send(msg) {
                     send_errors.push((pipeline.id, e));
@@ -4590,49 +4688,35 @@ where
             // Don't send a message to the browsing context that initiated this
             // focus operation. It already knows that it has gotten focus.
             if Some(pipeline.id) != initiator_pipeline_id {
-                let msg = if let Some(child_browsing_context_id) = child_browsing_context_id {
-                    // Focus the container element of `child_browsing_context_id`.
-                    ScriptThreadMessage::FocusIFrame(
+                if let Err(error) = pipeline.event_loop.send(
+                    ScriptThreadMessage::FocusDocumentAsPartOfFocusingSteps(
                         pipeline.id,
-                        child_browsing_context_id,
                         pipeline.focus_sequence,
-                    )
-                } else {
-                    // Focus the document.
-                    ScriptThreadMessage::FocusDocument(pipeline.id, pipeline.focus_sequence)
-                };
-                trace!("Sending {:?} to {}", msg, pipeline.id);
-                if let Err(e) = pipeline.event_loop.send(msg) {
-                    send_errors.push((pipeline.id, e));
+                        child_browsing_context_id,
+                    ),
+                ) {
+                    send_errors.push((pipeline.id, error));
                 }
-            } else {
-                trace!(
-                    "Not notifying {} - it's the initiator of this focus operation",
-                    pipeline.id
-                );
             }
             child_browsing_context_id = Some(pipeline.browsing_context_id);
         }
 
-        if let (Some(pipeline), Some(child_browsing_context_id)) =
-            (first_common_pipeline_in_chain, child_browsing_context_id)
-        {
+        if let Some(pipeline) = first_common_pipeline_in_chain {
             if Some(pipeline.id) != initiator_pipeline_id {
-                // Focus the container element of `child_browsing_context_id`.
-                let msg = ScriptThreadMessage::FocusIFrame(
-                    pipeline.id,
-                    child_browsing_context_id,
-                    pipeline.focus_sequence,
-                );
-                trace!("Sending {:?} to {}", msg, pipeline.id);
-                if let Err(e) = pipeline.event_loop.send(msg) {
-                    send_errors.push((pipeline.id, e));
+                if let Err(error) = pipeline.event_loop.send(
+                    ScriptThreadMessage::FocusDocumentAsPartOfFocusingSteps(
+                        pipeline.id,
+                        pipeline.focus_sequence,
+                        child_browsing_context_id,
+                    ),
+                ) {
+                    send_errors.push((pipeline.id, error));
                 }
             }
         }
 
-        for (pipeline_id, e) in send_errors {
-            self.handle_send_error(pipeline_id, e);
+        for (pipeline_id, error) in send_errors {
+            self.handle_send_error(pipeline_id, error);
         }
     }
 
@@ -4713,7 +4797,7 @@ where
                 let _ = response_sender.send(is_open);
             },
             WebDriverCommandMsg::FocusBrowsingContext(browsing_context_id) => {
-                self.handle_focus_remote_document_msg(browsing_context_id);
+                self.handle_focus_remote_browsing_context(browsing_context_id);
             },
             // TODO: This should use the ScriptThreadMessage::EvaluateJavaScript command
             WebDriverCommandMsg::ScriptCommand(browsing_context_id, cmd) => {
@@ -5054,9 +5138,16 @@ where
 
         // If the browsing context is focused, focus the document
         let msg = if is_focused {
-            ScriptThreadMessage::FocusDocument(pipeline_id, pipeline.focus_sequence)
+            ScriptThreadMessage::FocusDocumentAsPartOfFocusingSteps(
+                pipeline_id,
+                pipeline.focus_sequence,
+                None,
+            )
         } else {
-            ScriptThreadMessage::Unfocus(pipeline_id, pipeline.focus_sequence)
+            ScriptThreadMessage::UnfocusDocumentAsPartOfFocusingSteps(
+                pipeline_id,
+                pipeline.focus_sequence,
+            )
         };
         if let Err(e) = pipeline.event_loop.send(msg) {
             self.handle_send_error(pipeline_id, e);
@@ -5735,23 +5826,6 @@ where
             })
     }
 
-    /// Convert a webview to a flat list of active pipeline ids, for activating accessibility.
-    fn active_pipelines_for_webview(&self, webview_id: WebViewId) -> Vec<PipelineId> {
-        let mut result = vec![];
-        let mut browsing_context_ids = vec![BrowsingContextId::from(webview_id)];
-        while let Some(browsing_context_id) = browsing_context_ids.pop() {
-            let Some(browsing_context) = self.browsing_contexts.get(&browsing_context_id) else {
-                continue;
-            };
-            let Some(pipeline) = self.pipelines.get(&browsing_context.pipeline_id) else {
-                continue;
-            };
-            result.push(browsing_context.pipeline_id);
-            browsing_context_ids.extend(pipeline.children.iter().copied());
-        }
-        result
-    }
-
     /// Send the frame tree for the given webview to `Paint`.
     #[servo_tracing::instrument(skip_all)]
     fn set_frame_tree_for_webview(&mut self, webview_id: WebViewId) {
@@ -5759,35 +5833,55 @@ where
         // avoiding this panic would require a mechanism for dealing
         // with low-resource scenarios.
         let browsing_context_id = BrowsingContextId::from(webview_id);
-        if let Some(frame_tree) = self.browsing_context_to_sendable(browsing_context_id) {
-            if let Some(webview) = self.webviews.get_mut(&webview_id) {
-                if frame_tree.pipeline.id != webview.active_top_level_pipeline_id {
-                    webview.active_top_level_pipeline_id = frame_tree.pipeline.id;
-                    self.constellation_to_embedder_proxy.send(
-                        ConstellationToEmbedderMsg::AccessibilityTreeIdChanged(
-                            webview_id,
-                            webview.active_top_level_pipeline_id.into(),
-                        ),
-                    );
-                }
-            }
-
-            debug!("{}: Sending frame tree", browsing_context_id);
-            self.paint_proxy
-                .send(PaintMessage::SetFrameTreeForWebView(webview_id, frame_tree));
-        }
-
-        let Some(webview) = self.webviews.get(&webview_id) else {
+        let Some(frame_tree) = self.browsing_context_to_sendable(browsing_context_id) else {
             return;
         };
-        let active = webview.accessibility_active;
-        for pipeline_id in self.active_pipelines_for_webview(webview_id) {
+
+        let new_pipeline_id = frame_tree.pipeline.id;
+
+        debug!("{}: Sending frame tree", browsing_context_id);
+        self.paint_proxy
+            .send(PaintMessage::SetFrameTreeForWebView(webview_id, frame_tree));
+
+        let Some(webview) = self.webviews.get_mut(&webview_id) else {
+            return;
+        };
+        if webview.active_top_level_pipeline_id == Some(new_pipeline_id) {
+            return;
+        }
+
+        let old_pipeline_id = webview.active_top_level_pipeline_id;
+        let old_epoch = webview.active_top_level_pipeline_epoch;
+        let new_epoch = old_epoch.next();
+
+        let accessibility_active = webview.accessibility_active;
+
+        webview.active_top_level_pipeline_id = Some(new_pipeline_id);
+        webview.active_top_level_pipeline_epoch = new_epoch;
+
+        // Deactivate accessibility in the now-inactive top-level document in the WebView.
+        // This ensures that the document stops sending tree updates, since they will be
+        // discarded in libservo anyway, and also ensures that when accessibility is
+        // reactivated, the document sends the whole accessibility tree from scratch.
+        if let Some(old_pipeline_id) = old_pipeline_id {
             self.send_message_to_pipeline(
-                pipeline_id,
-                ScriptThreadMessage::SetAccessibilityActive(pipeline_id, active),
+                old_pipeline_id,
+                ScriptThreadMessage::SetAccessibilityActive(old_pipeline_id, false, old_epoch),
                 "Set accessibility active after closure",
             );
         }
+
+        // Forward activation to layout for the active top-level document in the WebView.
+        // There are two sites like this; this is the navigation (or bfcache traversal) site.
+        self.send_message_to_pipeline(
+            new_pipeline_id,
+            ScriptThreadMessage::SetAccessibilityActive(
+                new_pipeline_id,
+                accessibility_active,
+                new_epoch,
+            ),
+            "Set accessibility active after closure",
+        );
     }
 
     #[servo_tracing::instrument(skip_all)]

components/constellation/constellation_webview.rs

@@ -3,15 +3,15 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use embedder_traits::user_contents::UserContentManagerId;
-use embedder_traits::{GenericEmbedderProxy, InputEvent, MouseLeftViewportEvent, Theme};
+use embedder_traits::{InputEvent, MouseLeftViewportEvent, Theme};
 use euclid::Point2D;
 use log::warn;
 use rustc_hash::FxHashMap;
 use script_traits::{ConstellationInputEvent, ScriptThreadMessage};
+use servo_base::Epoch;
 use servo_base::id::{BrowsingContextId, PipelineId, WebViewId};
 use style_traits::CSSPixel;
 
-use super::embedder::ConstellationToEmbedderMsg;
 use crate::browsingcontext::BrowsingContext;
 use crate::pipeline::Pipeline;
 use crate::session_history::JointSessionHistory;
@@ -23,7 +23,9 @@ pub(crate) struct ConstellationWebView {
     webview_id: WebViewId,
 
     /// The [`PipelineId`] of the currently active pipeline at the top level of this WebView.
-    pub active_top_level_pipeline_id: PipelineId,
+    pub active_top_level_pipeline_id: Option<PipelineId>,
+    /// A counter for changes to [`Self::active_top_level_pipeline_id`].
+    pub active_top_level_pipeline_epoch: Epoch,
 
     /// The currently focused browsing context in this webview for key events.
     /// The focused pipeline is the current entry of the focused browsing
@@ -61,21 +63,15 @@ pub(crate) struct ConstellationWebView {
 
 impl ConstellationWebView {
     pub(crate) fn new(
-        embedder_proxy: &GenericEmbedderProxy<ConstellationToEmbedderMsg>,
         webview_id: WebViewId,
-        active_top_level_pipeline_id: PipelineId,
         focused_browsing_context_id: BrowsingContextId,
         user_content_manager_id: Option<UserContentManagerId>,
     ) -> Self {
-        embedder_proxy.send(ConstellationToEmbedderMsg::AccessibilityTreeIdChanged(
-            webview_id,
-            active_top_level_pipeline_id.into(),
-        ));
-
         Self {
             webview_id,
             user_content_manager_id,
-            active_top_level_pipeline_id,
+            active_top_level_pipeline_id: None,
+            active_top_level_pipeline_epoch: Epoch::default(),
             focused_browsing_context_id,
             hovered_browsing_context_id: None,
             last_mouse_move_point: Default::default(),

components/constellation/embedder.rs

@@ -2,7 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use accesskit::TreeId;
 use embedder_traits::{
     InputEventOutcome, JSValue, JavaScriptEvaluationError, JavaScriptEvaluationId,
     MediaSessionEvent, NewWebViewDetails, TraversalId,
@@ -48,7 +47,4 @@ pub enum ConstellationToEmbedderMsg {
     AllowNavigationRequest(WebViewId, PipelineId, ServoUrl),
     /// The history state has changed.
     HistoryChanged(WebViewId, Vec<ServoUrl>, usize),
-    /// Notifies the embedder that the AccessKit [`TreeId`] for the top-level document in this
-    /// WebView has been changed (or initially set).
-    AccessibilityTreeIdChanged(WebViewId, TreeId),
 }

components/constellation/process_manager.rs

@@ -65,6 +65,7 @@ impl ProcessManager {
         receiver
     }
 
+    #[servo_tracing::instrument(skip_all)]
     pub fn remove(&mut self, index: usize) {
         let (mut process, _) = self.processes.swap_remove(index);
         debug!("Removing process pid={}", process.pid());

components/constellation/tracing.rs

@@ -141,11 +141,15 @@ mod from_script {
                     target!("RemoveBroadcastChannelNameInRouter")
                 },
                 Self::ScheduleBroadcast(..) => target!("ScheduleBroadcast"),
+                Self::RegisterInterest(..) => target!("RegisterInterest"),
+                Self::UnregisterInterest(..) => target!("UnregisterInterest"),
                 Self::BroadcastStorageEvent(..) => target!("BroadcastStorageEvent"),
                 Self::ChangeRunningAnimationsState(..) => target!("ChangeRunningAnimationsState"),
                 Self::CreateCanvasPaintThread(..) => target!("CreateCanvasPaintThread"),
-                Self::Focus(..) => target!("Focus"),
-                Self::FocusRemoteDocument(..) => target!("FocusRemoteDocument"),
+                Self::FocusAncestorBrowsingContextsForFocusingSteps(..) => {
+                    target!("FocusAncestorBrowsingContextsForFocusingSteps")
+                },
+                Self::FocusRemoteBrowsingContext(..) => target!("FocusRemoteBrowsingContext"),
                 Self::GetTopForBrowsingContext(..) => target!("GetTopForBrowsingContext"),
                 Self::GetBrowsingContextInfo(..) => target!("GetBrowsingContextInfo"),
                 Self::GetDocumentOrigin(..) => target!("GetDocumentOrigin"),
@@ -187,6 +191,8 @@ mod from_script {
                     target!("RespondToScreenshotReadinessRequest")
                 },
                 Self::TriggerGarbageCollection => target!("TriggerGarbageCollection"),
+                Self::AcquireWakeLock(..) => target!("AcquireWakeLock"),
+                Self::ReleaseWakeLock(..) => target!("ReleaseWakeLock"),
             }
         }
     }

components/default-resources/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "servo-default-resources"
+version.workspace = true
+authors.workspace = true
+repository.workspace = true
+description.workspace = true
+license.workspace = true
+edition.workspace = true
+publish.workspace = true
+rust-version.workspace = true
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+embedder_traits = { workspace = true }

components/default-resources/lib.rs

@@ -0,0 +1,39 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use std::path::PathBuf;
+
+use embedder_traits::resources::{Resource, ResourceReaderMethods};
+
+/// A default resource reader that provides baked in resources.
+pub struct DefaultResourceReader;
+
+impl ResourceReaderMethods for DefaultResourceReader {
+    fn sandbox_access_files(&self) -> Vec<PathBuf> {
+        vec![]
+    }
+    fn sandbox_access_files_dirs(&self) -> Vec<PathBuf> {
+        vec![]
+    }
+    fn read(&self, file: Resource) -> Vec<u8> {
+        match file {
+            Resource::BluetoothBlocklist => &include_bytes!("resources/gatt_blocklist.txt")[..],
+            Resource::DomainList => &include_bytes!("resources/public_domains.txt")[..],
+            Resource::HstsPreloadList => &include_bytes!("resources/hsts_preload.fstmap")[..],
+            Resource::BadCertHTML => &include_bytes!("resources/badcert.html")[..],
+            Resource::NetErrorHTML => &include_bytes!("resources/neterror.html")[..],
+            Resource::BrokenImageIcon => &include_bytes!("resources/rippy.png")[..],
+            Resource::CrashHTML => &include_bytes!("resources/crash.html")[..],
+            Resource::DirectoryListingHTML => {
+                &include_bytes!("resources/directory-listing.html")[..]
+            },
+            Resource::AboutMemoryHTML => &include_bytes!("resources/about-memory.html")[..],
+            Resource::DebuggerJS => &include_bytes!("resources/debugger.js")[..],
+            Resource::JsonViewerHTML => &include_bytes!("resources/json-viewer.html")[..],
+        }
+        .to_owned()
+    }
+}
+
+embedder_traits::submit_resource_reader!(&DefaultResourceReader);

components/default-resources/resources/debugger.js

@@ -0,0 +1,611 @@
+if ("dbg" in this) {
+    throw new Error("Debugger script must not run more than once!");
+}
+
+const dbg = new Debugger;
+const debuggeesToPipelineIds = new Map;
+const debuggeesToWorkerIds = new Map;
+const sourceIdsToScripts = new Map;
+const frameActorsToFrames = new Map;
+const environmentActorsToEnvironments = new Map;
+
+// <https://searchfox.org/firefox-main/source/devtools/server/actors/thread.js#155>
+// Possible values for the `why.type` attribute in "paused" event
+const PAUSE_REASONS = {
+  INTERRUPTED: "interrupted", // Associated with why.onNext attribute
+  RESUME_LIMIT: "resumeLimit",
+};
+
+// Find script by scriptId within a script tree
+function findScriptById(script, scriptId) {
+    if (script.sourceStart === scriptId) {
+        return script;
+    }
+    for (const child of script.getChildScripts()) {
+        const found = findScriptById(child, scriptId);
+        if (found) return found;
+    }
+    return null;
+}
+
+// Walk script tree and call callback for each script
+function walkScriptTree(script, callback) {
+    callback(script);
+    for (const child of script.getChildScripts()) {
+        walkScriptTree(child, callback);
+    }
+}
+
+// Find a key by a value in a map
+function findKeyByValue(map, search) {
+    for (const [key, value] of map) {
+        if (value === search) return key;
+    }
+    return undefined;
+}
+
+dbg.uncaughtExceptionHook = function(error) {
+    console.error(`[debugger] Uncaught exception at ${error.fileName}:${error.lineNumber}:${error.columnNumber}: ${error.name}: ${error.message}`);
+};
+
+dbg.onNewScript = function(script) {
+    // TODO: handle wasm (`script.source.introductionType == wasm`)
+    sourceIdsToScripts.set(script.source.id, script);
+    notifyNewSource({
+        pipelineId: debuggeesToPipelineIds.get(script.global),
+        workerId: debuggeesToWorkerIds.get(script.global),
+        spidermonkeyId: script.source.id,
+        url: script.source.url,
+        urlOverride: script.source.displayURL,
+        text: script.source.text,
+        introductionType: script.source.introductionType ?? null,
+    });
+};
+
+// Track a new debuggee global
+addEventListener("addDebuggee", event => {
+    const {global, pipelineId, workerId} = event;
+    const debuggerObject = dbg.addDebuggee(global);
+    debuggeesToPipelineIds.set(debuggerObject, pipelineId);
+    if (workerId !== undefined) {
+        debuggeesToWorkerIds.set(debuggerObject, workerId);
+    }
+});
+
+
+// <https://searchfox.org/mozilla-central/source/devtools/server/actors/object/previewers.js#80>
+const previewers = {
+    Function: [],
+    Array: [],
+    Object: [],
+    // TODO: Add Map, FormData etc
+};
+
+// Convert debuggee value to property descriptor value
+// <https://searchfox.org/firefox-main/source/devtools/server/actors/object/utils.js#116>
+function createValueGrip(value, depth = 0) {
+    switch (typeof value) {
+        case "undefined":
+            return { valueType: "undefined" };
+        case "boolean":
+            return { valueType: "boolean", booleanValue: value };
+        case "number":
+            if (value === Infinity) {
+                return { valueType: "Infinity" };
+            } else if (value === -Infinity) {
+                return { valueType: "-Infinity" };
+            } else if (Number.isNaN(value)) {
+                return { valueType: "NaN" };
+            } else if (Object.is(value, -0)) {
+                return { valueType: "-0" };
+            }
+            return { valueType: "number", numberValue: value };
+        case "string":
+            return { valueType: "string", stringValue: value };
+        case "object":
+            if (value === null) {
+                return { valueType: "null" };
+            }
+            // Debugger.Object - get preview using registered previewers
+            // <https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/debugger.object/index.html>
+            return {
+                valueType: "object",
+                objectClass: value.class,
+                preview: getPreview(value, depth),
+            };
+        default:
+            return { valueType: "string", stringValue: String(value) };
+    }
+}
+
+// Extract own properties from a debuggee object
+// <https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/debugger.object/index.html#function-properties-of-the-debugger-object-prototype>
+function extractOwnProperties(obj, depth) {
+    const ownProperties = [];
+    let totalLength = 0;
+
+    let names;
+    try {
+        names = obj.getOwnPropertyNames();
+        totalLength = names.length;
+    } catch (e) {
+        return { ownProperties, ownPropertiesLength: 0 };
+    }
+
+    for (const name of names) {
+        try {
+            const desc = obj.getOwnPropertyDescriptor(name);
+            if (desc) {
+                const prop = {
+                    name: name,
+                    configurable: desc.configurable ?? false,
+                    enumerable: desc.enumerable ?? false,
+                    writable: desc.writable ?? false,
+                    isAccessor: desc.get !== undefined || desc.set !== undefined,
+                    value: createValueGrip(undefined, depth + 1),
+                };
+
+                if (desc.value !== undefined) {
+                    prop.value = createValueGrip(desc.value, depth + 1);
+                } else if (desc.get) {
+                    try {
+                        const result = desc.get.call(obj);
+                        if (result && "return" in result) {
+                            prop.value = createValueGrip(result.return, depth + 1);
+                        }
+                    } catch (e) { }
+                }
+
+                ownProperties.push(prop);
+            }
+        } catch (e) {
+            // For now skip properties that throw on access
+        }
+    }
+
+    return { ownProperties, ownPropertiesLength: totalLength };
+}
+
+// <https://searchfox.org/mozilla-central/source/devtools/server/actors/object/previewers.js#125>
+previewers.Function.push(function FunctionPreviewer(obj, depth) {
+    const { ownProperties, ownPropertiesLength } = extractOwnProperties(obj, depth);
+    let function_details = {
+        name: obj.name,
+        displayName: obj.displayName,
+        parameterNames: obj.parameterNames ? obj.parameterNames: [],
+        isAsync: obj.isAsyncFunction,
+        isGenerator: obj.isGeneratorFunction,
+    }
+
+    if (depth > 1) {
+        return { kind: "Object", function: function_details, ownPropertiesLength };
+    }
+
+    return {
+        kind: "Object",
+        ownProperties,
+        ownPropertiesLength,
+        function: function_details
+    };
+});
+
+// <https://searchfox.org/mozilla-central/source/devtools/server/actors/object/previewers.js#172>
+previewers.Array.push(function ArrayPreviewer(obj, depth) {
+    const lengthDescriptor = obj.getOwnPropertyDescriptor("length");
+    const length = lengthDescriptor ? lengthDescriptor.value : 0;
+
+    if (depth > 1) {
+        return {
+            kind: "ArrayLike",
+            arrayLength: length,
+        };
+    }
+
+    const items = [];
+    for (let i = 0; i < length; i++) {
+        try {
+            const desc = obj.getOwnPropertyDescriptor(i);
+            if (desc && desc.value !== undefined) {
+                const grip = createValueGrip(desc.value, depth);
+                delete grip.preview;
+                items.push(grip);
+            }
+        } catch (e) {
+            // For now skip properties that throw on access
+        }
+    }
+
+    return {
+        kind: "ArrayLike",
+        arrayLength: length,
+        items: items,
+    };
+});
+
+// Generic fallback for object previewer
+// <https://searchfox.org/mozilla-central/source/devtools/server/actors/object/previewers.js#856>
+previewers.Object.push(function ObjectPreviewer(obj, depth) {
+    const { ownProperties, ownPropertiesLength } = extractOwnProperties(obj, depth);
+
+    if (depth > 1) {
+       return { kind: "Object", ownPropertiesLength };
+    }
+
+    return {
+        kind: "Object",
+        ownProperties,
+        ownPropertiesLength,
+    };
+});
+
+function getPreview(obj, depth) {
+    const className = obj.class;
+
+    // <https://searchfox.org/mozilla-central/source/devtools/server/actors/object.js#295>
+    const typePreviewers = previewers[className] || previewers.Object;
+    for (const previewer of typePreviewers) {
+        const result = previewer(obj, depth);
+        if (result) return result;
+    }
+
+    return { ownProperties: [], ownPropertiesLength: 0 };
+}
+
+// Evaluate some javascript code in the global context of the debuggee
+// See executeInGlobal() at <https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/debugger.object/index.html#function-properties-of-the-debugger-object-prototype>
+addEventListener("eval", event => {
+    const {code, pipelineId, workerId, frameActorId} = event;
+
+    let completionValue;
+    if (frameActorId) {
+        const frame = frameActorsToFrames.get(frameActorId);
+        // <https://searchfox.org/firefox-main/source/js/src/doc/Debugger/Debugger.Frame.md#223>
+        if (frame?.onStack) {
+            completionValue = frame.eval(code);
+        } else {
+            completionValue = { throw: "Frame not available" };
+        }
+    } else {
+        const object = workerId !== undefined ?
+            findKeyByValue(debuggeesToWorkerIds, workerId) :
+            findKeyByValue(debuggeesToPipelineIds, pipelineId);
+        completionValue = object.executeInGlobal(code);
+    }
+
+    // Completion values: <https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#completion-values>
+    let resultValue;
+    if (completionValue === null) {
+        resultValue = { completionType: "terminated", value: createValueGrip(undefined), hasException: false };
+    } else if ("throw" in completionValue) {
+        // See adoptDebuggeeValue() in <https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/debugger/index.html>
+        // <https://searchfox.org/firefox-main/source/devtools/server/actors/webconsole/eval-with-debugger.js#312>
+        // we probably don't need adoptDebuggeeValue, as we only have one debugger instance for now
+        // let value = dbg.adoptDebuggeeValue(completionValue.throw);
+        resultValue = { completionType: "throw", value: createValueGrip(completionValue.throw), hasException: true };
+    } else if ("return" in completionValue) {
+        resultValue = { completionType: "return", value: createValueGrip(completionValue.return), hasException: false };
+    }
+
+    // To avoid recursion errors in the WebIDL, preview needs to live outside of the property descriptor
+    if (resultValue.value.preview) {
+        resultValue.preview = resultValue.value.preview;
+        delete resultValue.value.preview;
+    }
+
+    evalResult(event, resultValue);
+});
+
+addEventListener("getPossibleBreakpoints", event => {
+    const {spidermonkeyId} = event;
+    const script = sourceIdsToScripts.get(spidermonkeyId);
+    const result = [];
+    walkScriptTree(script, (currentScript) => {
+        for (const location of currentScript.getPossibleBreakpoints()) {
+            location["scriptId"] = currentScript.sourceStart;
+            result.push(location);
+        }
+    });
+    getPossibleBreakpointsResult(event, result);
+});
+
+function createFrameActor(frame, pipelineId) {
+    let frameActorId = findKeyByValue(frameActorsToFrames, frame);
+    if (!frameActorId) {
+        // TODO: Check if we already have an actor for this frame
+        frameActorId = registerFrameActor(pipelineId, {
+            // TODO: Some properties throw if terminated is true
+            // TODO: arguments: frame.arguments,
+            displayName: frame.script.displayName,
+            onStack: frame.onStack,
+            oldest: frame.older == null,
+            terminated: frame.terminated,
+            type_: frame.type,
+            url: frame.script.url,
+        });
+
+        if (!frameActorId) {
+            console.error("[debugger] Couldn't create frame");
+            return undefined;
+        }
+        frameActorsToFrames.set(frameActorId, frame);
+    }
+
+    return frameActorId;
+}
+
+function handlePauseAndRespond(frame, pauseReason) {
+    dbg.onEnterFrame = undefined;
+    clearSteppingHooks(frame);
+
+    // Get the pipeline ID for this debuggee
+    const pipelineId = debuggeesToPipelineIds.get(frame.script.global);
+    if (!pipelineId) {
+        console.error("[debugger] No pipeline ID for frame's global");
+        return undefined;
+    }
+
+    let frameActorId = createFrameActor(frame, pipelineId);
+
+    // <https://github.com/mozilla-firefox/firefox/blob/63719d122f9214f37fd1d285a91897b8345b88b0/js/src/doc/Debugger/Debugger.Script.md?plain=1#L293-L303>
+    const offset = frame.offset;
+    const offsetMetadata = frame.script.getOffsetMetadata(offset);
+    const frameOffset = {
+        frameActorId,
+        column: offsetMetadata.columnNumber - 1,
+        line: offsetMetadata.lineNumber
+    };
+
+    // Notify devtools and enter pause loop. This blocks until Resume.
+    pauseAndRespond(
+        pipelineId,
+        frameOffset,
+        pauseReason
+    );
+
+    // <https://web.archive.org/web/20251212212538/https://firefox-source-docs.mozilla.org/js/Debugger/Conventions.html#resumption-values>
+    // Return undefined to continue execution normally after resume.
+    return undefined;
+}
+
+addEventListener("frames", event => {
+    const {pipelineId, start, count} = event;
+    let frameList = handleListFrames(pipelineId, start, count);
+
+    listFramesResult(frameList);
+})
+
+// <https://searchfox.org/firefox-main/source/devtools/server/actors/thread.js#1425>
+function handleListFrames(pipelineId, start, count) {
+    let frame = dbg.getNewestFrame()
+
+    const walkToParentFrame = () => {
+        if (!frame) {
+            return;
+        }
+
+        const currentFrame = frame;
+        frame = null;
+
+        if (currentFrame.older) {
+            frame = currentFrame.older;
+        }
+    }
+
+    let i = 0;
+    while (frame && i < start) {
+      walkToParentFrame();
+      i++;
+    }
+
+    // Return count frames, or all remaining frames if count is not defined.
+    const frames = [];
+    for (; frame && (!count || i < start + count); i++, walkToParentFrame()) {
+      const frameActorId = createFrameActor(frame, pipelineId);
+      frames.push(frameActorId);
+    }
+
+    return frames;
+}
+
+addEventListener("setBreakpoint", event => {
+    const {spidermonkeyId, scriptId, offset} = event;
+    const script = sourceIdsToScripts.get(spidermonkeyId);
+    const target = findScriptById(script, scriptId);
+    if (target) {
+        target.setBreakpoint(offset, {
+            // setBreakpoint(offset, handler) in <https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/debugger.script/index.html#function-properties-of-the-debugger-script-prototype-object>
+            // The hit handler receives a Debugger.Frame instance representing the currently executing stack frame.
+            hit: (frame) => handlePauseAndRespond(frame, {type_: "breakpoint"})
+        });
+    }
+});
+
+// <https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/debugger.frame/index.html>
+addEventListener("interrupt", event => {
+    dbg.onEnterFrame = (frame) => handlePauseAndRespond(
+        frame,
+        { type_: PAUSE_REASONS.INTERRUPTED, onNext: true }
+    );
+});
+
+function makeSteppingHooks(steppingType, startFrame) {
+    return {
+        onEnterFrame: (frame) => {
+            const { onStep, onPop } = makeSteppingHooks("next", frame);
+            frame.onStep = onStep;
+            frame.onPop = onPop;
+        },
+        onStep: () => {
+            const meta = startFrame.script.getOffsetMetadata(startFrame.offset);
+            if (meta.isBreakpoint && meta.isStepStart) {
+                return handlePauseAndRespond(startFrame, { type_: PAUSE_REASONS.RESUME_LIMIT });
+            }
+        },
+        onPop: (completion) => {
+            this.reportedPop = true;
+            suspendedFrame = startFrame;
+            if (steppingType !== "finish") {
+                // TODO: completion contains the return value, we have to send it back
+                // <https://searchfox.org/firefox-main/source/devtools/server/actors/thread.js#1026>
+                return handlePauseAndRespond(startFrame, { type_: steppingType });
+            }
+            attachSteppingHooks("next", startFrame);
+        },
+    }
+}
+
+function getNextStepFrame(frame) {
+    const endOfFrame = frame.reportedPop;
+    const stepFrame = endOfFrame ? frame.older : frame;
+    if (!stepFrame || !stepFrame.script) {
+      return null;
+    }
+    return stepFrame;
+}
+
+// <https://searchfox.org/firefox-main/source/devtools/server/actors/thread.js#1235>
+function attachSteppingHooks(steppingType, frame) {
+    if (steppingType === "finish" && frame.reportedPop) {
+        steppingType = "next";
+    }
+
+    const stepFrame = getNextStepFrame(frame);
+    if (!stepFrame) {
+        steppingType = "step";
+    }
+
+    const { onEnterFrame, onStep, onPop } = makeSteppingHooks(
+        steppingType,
+        frame,
+    );
+
+    if (steppingType === "step") {
+        dbg.onEnterFrame = onEnterFrame;
+    }
+
+    if (stepFrame) {
+        switch (steppingType) {
+            case "step":
+            case "next":
+                if (stepFrame.script) {
+                    stepFrame.onStep = onStep;
+                }
+            case "finish":
+                stepFrame.onPop = onPop;
+                break;
+        }
+    }
+}
+
+function clearSteppingHooks(suspendedFrame) {
+    if (suspendedFrame) {
+        suspendedFrame.onStep = undefined;
+        suspendedFrame.onPop = undefined;
+    }
+    let frame = this.youngestFrame;
+    if (frame?.onStack) {
+        while (frame) {
+            frame.onStep = undefined;
+            frame.onPop = undefined;
+            frame = frame.older;
+        }
+    }
+}
+
+// <https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#resuming-a-thread>
+addEventListener("resume", event => {
+    const {resumeLimitType: steppingType, frameActorID} = event;
+    let frame = dbg.getNewestFrame();
+    if (frameActorID) {
+        frame = frameActorsToFrames.get(frameActorID);
+        if (!frame) {
+            console.error("[debugger] Couldn't find frame");
+        }
+    }
+    if (steppingType) {
+        attachSteppingHooks(steppingType, frame);
+    } else {
+        clearSteppingHooks(frame);
+    }
+});
+
+// <https://firefox-source-docs.mozilla.org/devtools-user/debugger-api/debugger.script/index.html#function-properties-of-the-debugger-script-prototype-object>
+// There may be more than one breakpoint at the same offset with different handlers, but we don’t handle that case for now.
+addEventListener("clearBreakpoint", event => {
+    const {spidermonkeyId, scriptId, offset} = event;
+    const script = sourceIdsToScripts.get(spidermonkeyId);
+    const target = findScriptById(script, scriptId);
+    if (target) {
+        // If the instance refers to a JSScript, remove all breakpoints set in this script at that offset.
+        target.clearAllBreakpoints(offset);
+    }
+});
+
+// TODO: Get variables (scopes don't show if they don't have a variable)
+function createEnvironmentActor(environment) {
+    let actor = findKeyByValue(environmentActorsToEnvironments, environment);
+
+    if (!actor) {
+        let info = {};
+        if (environment.type == "declarative") {
+            info.type_ = environment.calleeScript ? "function" : "block";
+        } else {
+            info.type_ = environment.type;
+        }
+
+        info.scopeKind = environment.scopeKind;
+
+        if (environment.calleeScript) {
+            info.functionDisplayName = environment.calleeScript.displayName;
+        }
+
+        let parent = null;
+        if (environment.parent) {
+            parent = createEnvironmentActor(environment.parent);
+        }
+
+        if (environment.type == "declarative") {
+            info.bindingVariables = buildBindings(environment)
+        }
+
+        actor = registerEnvironmentActor(info, parent);
+        environmentActorsToEnvironments.set(actor, environment);
+    }
+
+    return actor;
+}
+
+function buildBindings(environment) {
+    let bindingVars = [];
+    for (const name of environment.names()) {
+        const value = environment.getVariable(name);
+        const property = {
+            name: name,
+            configurable: false,
+            enumerable: true,
+            writable: !value?.optimizedOut,
+            isAccessor: false,
+            value: createValueGrip(value),
+        };
+
+        // To avoid recursion errors in the WebIDL, preview needs to live outside of the property descriptor
+        let preview = undefined;
+        if (property.value.preview) {
+            preview = property.value.preview;
+            delete property.value.preview;
+        }
+
+        bindingVars.push({ property, preview });
+    }
+    return bindingVars;
+}
+
+// Get a `Debugger.Environment` instance within which evaluation is taking place.
+// <https://searchfox.org/firefox-main/source/devtools/server/actors/frame.js#109>
+addEventListener("getEnvironment", event => {
+    const {frameActorId} = event;
+    frame = frameActorsToFrames.get(frameActorId);
+
+    const actor = createEnvironmentActor(frame.environment);
+    getEnvironmentResult(actor);
+});

components/default-resources/resources/json-viewer.html

@@ -0,0 +1,269 @@
+<html>
+  <head>
+    <style>
+      body {
+        font-family: monospace;
+        margin: 0;
+        padding: 0;
+        background: #fff;
+        color: #333;
+      }
+
+      #json-raw {
+        display: none;
+      }
+
+      #viewer {
+        display: none;
+        padding: 0.5em 1em;
+        line-height: 1.5;
+
+        &.active {
+          display: block;
+        }
+      }
+
+      #toolbar {
+        display: flex;
+        gap: 1em;
+        padding: 0.5em;
+        align-items: center;
+        background: #f5f5f5;
+        border-bottom: 1px solid #ddd;
+
+        & button {
+          min-width: 5em;
+
+          &.active {
+            background: #ddd;
+            font-weight: bold;
+          }
+        }
+      }
+
+      #raw-view {
+        display: none;
+        padding: 0.5em 1em;
+        white-space: pre-wrap;
+        word-break: break-all;
+
+        &.active {
+          display: block;
+        }
+      }
+
+      .json-error {
+        padding: 0.5em 1em;
+        color: #c00;
+        font-weight: bold;
+      }
+
+      /* Syntax highlighting for Json data types */
+      .json-key {
+        color: #881391;
+      }
+
+      .json-string {
+        color: #1a1aa6;
+      }
+
+      .json-number {
+        color: #1c00cf;
+      }
+
+      .json-boolean {
+        color: #0d22aa;
+      }
+
+      .json-null {
+        color: #808080;
+      }
+
+      /* Collapsible tree */
+      .toggle {
+        cursor: pointer;
+        user-select: none;
+
+        &::before {
+          content: "\25BC";
+          display: inline-block;
+          width: 1em;
+          transition: transform 0.1s;
+        }
+
+        &.collapsed::before {
+          transform: rotate(-90deg);
+        }
+      }
+
+      .collapsible {
+        margin-left: 1.5em;
+
+        &.hidden {
+          display: none;
+        }
+      }
+
+      .bracket {
+        color: #333;
+      }
+
+      .comma {
+        color: #333;
+      }
+
+      .line {
+        padding-left: 0;
+      }
+    </style>
+    <script>
+      // Shortcut to create an element with an optional class and text content.
+      function createElement(name, classes = null, textContent = null) {
+        let node = document.createElement(name);
+        if (classes) {
+          node.className = classes;
+        }
+        if (textContent) {
+          node.textContent = textContent;
+        }
+        return node;
+      }
+
+      function renderNode(value, container) {
+        if (value === null) {
+          let s = createElement("span", "json-null", "null");
+          container.append(s);
+        } else if (typeof value === "boolean") {
+          let s = createElement("span", "json-boolean", String(value));
+          container.append(s);
+        } else if (typeof value === "number") {
+          let s = createElement("span", "json-number", String(value));
+          container.append(s);
+        } else if (typeof value === "string") {
+          let s = createElement("span", "json-string", JSON.stringify(value));
+          container.append(s);
+        } else if (Array.isArray(value)) {
+          renderArray(value, container);
+        } else if (typeof value === "object") {
+          renderObject(value, container);
+        }
+      }
+
+      function renderObject(obj, container) {
+        let keys = Object.keys(obj);
+        if (keys.length === 0) {
+          container.append(createElement("span", "bracket", "{}"));
+          return;
+        }
+
+        let toggle = createElement("span", "toggle");
+        container.append(toggle);
+
+        container.append(createElement("span", "bracket", "{"));
+
+        let inner = createElement("div", "collapsible");
+        container.append(inner);
+
+        keys.forEach((key, i) => {
+          let line = createElement("div", "line");
+          line.append(createElement("span", "json-key", JSON.stringify(key)));
+          line.append(document.createTextNode(": "));
+          renderNode(obj[key], line);
+          if (i < keys.length - 1) {
+            line.append(createElement("span", "comma", ","));
+          }
+          inner.append(line);
+        });
+
+        container.append(createElement("span", "bracket", "}"));
+
+        toggle.onclick = function () {
+          toggle.classList.toggle("collapsed");
+          inner.classList.toggle("hidden");
+        };
+      }
+
+      function renderArray(arr, container) {
+        if (arr.length === 0) {
+          container.append(createElement("span", "bracket", "[]"));
+          return;
+        }
+
+        let toggle = createElement("span", "toggle");
+        container.append(toggle);
+
+        container.append(createElement("span", "bracket", "["));
+
+        let inner = createElement("div", "collapsible");
+        container.append(inner);
+
+        arr.forEach((item, i) => {
+          let line = createElement("div", "line");
+          renderNode(item, line);
+          if (i < arr.length - 1) {
+            line.append(createElement("span", "comma", ","));
+          }
+          inner.append(line);
+        });
+
+        container.append(createElement("span", "bracket", "]"));
+
+        toggle.onclick = function () {
+          toggle.classList.toggle("collapsed");
+          inner.classList.toggle("hidden");
+        };
+      }
+
+      document.addEventListener("DOMContentLoaded", function () {
+        const viewer = document.getElementById("viewer");
+        const prettyButton = document.getElementById("pretty-toggle");
+        const rawButton = document.getElementById("raw-toggle");
+        const rawView = document.getElementById("raw-view");
+        const rawText = rawView.innerText;
+
+        let data;
+        let parseError = null;
+        try {
+          data = JSON.parse(rawText);
+        } catch (e) {
+          parseError = e;
+        }
+
+        if (parseError) {
+          let errDiv = createElement(
+            "div",
+            "json-error",
+            "Invalid JSON: " + parseError.message,
+          );
+          viewer.append(errDiv);
+          viewer.append(createElement("pre", null, rawText));
+        } else {
+          renderNode(data, viewer);
+          rawView.textContent = JSON.stringify(data, null, 2);
+        }
+
+        // Toggle buttons
+        prettyButton.onclick = function () {
+          viewer.classList.add("active");
+          rawView.classList.remove("active");
+
+          prettyButton.classList.add("active");
+          rawButton.classList.remove("active");
+        };
+        rawButton.onclick = function () {
+          rawView.classList.add("active");
+          viewer.classList.remove("active");
+
+          rawButton.classList.add("active");
+          prettyButton.classList.remove("active");
+        };
+      });
+    </script>
+  </head>
+  <body>
+    <div id="toolbar">
+      <button id="pretty-toggle" class="active">Pretty</button>
+      <button id="raw-toggle">Raw</button>
+    </div>
+    <div id="viewer" class="active"></div>
+    <pre id="raw-view">

components/devtools/actor.rs

@@ -49,7 +49,6 @@ impl ActorError {
 
 /// A common trait for all devtools actors that encompasses an immutable name
 /// and the ability to process messages that are directed to particular actors.
-/// TODO: ensure the name is immutable
 pub(crate) trait Actor: Any + ActorAsAny + Send + Sync + MallocSizeOf {
     fn handle_message(
         &self,
@@ -157,11 +156,19 @@ impl ActorRegistry {
     }
 
     /// Create a unique name based on a monotonically increasing suffix
-    /// TODO: Merge this with `register/register_later` and don't allow to
+    /// TODO: Merge this with `register` and don't allow to
     /// create new names without registering an actor.
     pub fn new_name<T: Actor>(&self) -> String {
         let suffix = self.next.fetch_add(1, Ordering::Relaxed);
-        format!("{}{}", Self::base_name::<T>(), suffix)
+        let base = Self::base_name::<T>();
+
+        // Firefox DevTools client requires "/workerTarget" in actor name to recognize workers
+        // <https://searchfox.org/firefox-main/source/devtools/client/fronts/watcher.js#65>
+        if base.contains("WorkerTarget") {
+            format!("/workerTarget{}", suffix)
+        } else {
+            format!("{}{}", base, suffix)
+        }
     }
 
     /// Add an actor to the registry of known actors that can receive messages.

components/devtools/actors/blackboxing.rs

@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use malloc_size_of_derive::MallocSizeOf;
+
+use crate::ActorMsg;
+use crate::actor::{Actor, ActorEncode, ActorRegistry};
+
+#[derive(MallocSizeOf)]
+pub(crate) struct BlackboxingActor {
+    name: String,
+}
+
+impl Actor for BlackboxingActor {
+    fn name(&self) -> String {
+        self.name.clone()
+    }
+}
+
+impl BlackboxingActor {
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
+    }
+}
+
+impl ActorEncode<ActorMsg> for BlackboxingActor {
+    fn encode(&self, _: &ActorRegistry) -> ActorMsg {
+        ActorMsg { actor: self.name() }
+    }
+}

components/devtools/actors/breakpoint.rs

@@ -62,8 +62,9 @@ impl Actor for BreakpointListActor {
 
                 let browsing_context_actor =
                     registry.find::<BrowsingContextActor>(&self.browsing_context_name);
-                let thread = registry.find::<ThreadActor>(&browsing_context_actor.thread);
-                let source = thread
+                let thread_actor =
+                    registry.find::<ThreadActor>(&browsing_context_actor.thread_name);
+                let source = thread_actor
                     .source_manager
                     .find_source(registry, &source_url)
                     .ok_or(ActorError::Internal)?;
@@ -98,8 +99,9 @@ impl Actor for BreakpointListActor {
 
                 let browsing_context_actor =
                     registry.find::<BrowsingContextActor>(&self.browsing_context_name);
-                let thread = registry.find::<ThreadActor>(&browsing_context_actor.thread);
-                let source = thread
+                let thread_actor =
+                    registry.find::<ThreadActor>(&browsing_context_actor.thread_name);
+                let source = thread_actor
                     .source_manager
                     .find_source(registry, &source_url)
                     .ok_or(ActorError::Internal)?;
@@ -124,11 +126,14 @@ impl Actor for BreakpointListActor {
 }
 
 impl BreakpointListActor {
-    pub fn new(name: String, browsing_context_name: String) -> Self {
-        Self {
-            name,
+    pub fn register(registry: &ActorRegistry, browsing_context_name: String) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
             browsing_context_name,
-        }
+        };
+        registry.register::<Self>(actor);
+        name
     }
 }
 

components/devtools/actors/browsing_context.rs

@@ -139,13 +139,13 @@ pub(crate) struct BrowsingContextActor {
     active_pipeline_id: AtomicRefCell<PipelineId>,
     active_outer_window_id: AtomicRefCell<DevtoolsOuterWindowId>,
     pub browsing_context_id: DevtoolsBrowsingContextId,
-    accessibility: String,
+    accessibility_name: String,
     pub console_name: String,
     css_properties_name: String,
-    pub(crate) inspector: String,
+    pub(crate) inspector_name: String,
     reflow_name: String,
     style_sheets_name: String,
-    pub thread: String,
+    pub thread_name: String,
     _tab: String,
     // Different pipelines may run on different script threads.
     // These should be kept around even when the active pipeline is updated,
@@ -197,7 +197,8 @@ impl Actor for BrowsingContextActor {
 
 impl BrowsingContextActor {
     #[expect(clippy::too_many_arguments)]
-    pub(crate) fn new(
+    pub(crate) fn register(
+        registry: &ActorRegistry,
         console_name: String,
         browser_id: DevtoolsBrowserId,
         browsing_context_id: DevtoolsBrowsingContextId,
@@ -205,8 +206,7 @@ impl BrowsingContextActor {
         pipeline_id: PipelineId,
         outer_window_id: DevtoolsOuterWindowId,
         script_sender: GenericSender<DevtoolScriptControlMsg>,
-        registry: &ActorRegistry,
-    ) -> BrowsingContextActor {
+    ) -> String {
         let name = registry.new_name::<BrowsingContextActor>();
         let DevtoolsPageInfo {
             title,
@@ -215,8 +215,7 @@ impl BrowsingContextActor {
             ..
         } = page_info;
 
-        let accessibility_actor =
-            AccessibilityActor::new(registry.new_name::<AccessibilityActor>());
+        let accessibility_name = AccessibilityActor::register(registry);
 
         let properties = (|| {
             let (properties_sender, properties_receiver) = generic_channel::channel()?;
@@ -224,25 +223,21 @@ impl BrowsingContextActor {
             properties_receiver.recv().ok()
         })()
         .unwrap_or_default();
-        let css_properties_actor =
-            CssPropertiesActor::new(registry.new_name::<CssPropertiesActor>(), properties);
+        let css_properties_name = CssPropertiesActor::register(registry, properties);
 
-        let inspector = InspectorActor::register(registry, name.clone());
+        let inspector_name = InspectorActor::register(registry, name.clone());
 
-        let reflow_actor = ReflowActor::new(registry.new_name::<ReflowActor>());
+        let reflow_name = ReflowActor::register(registry);
 
-        let style_sheets_actor = StyleSheetsActor::new(registry.new_name::<StyleSheetsActor>());
+        let style_sheets_name = StyleSheetsActor::register(registry);
 
-        let tab_descriptor_actor =
-            TabDescriptorActor::new(registry, name.clone(), is_top_level_global);
+        let tab_descriptor_name =
+            TabDescriptorActor::register(registry, name.clone(), is_top_level_global);
 
-        let thread = ThreadActor::new(
-            registry.new_name::<ThreadActor>(),
-            script_sender.clone(),
-            Some(name.clone()),
-        );
+        let thread_name =
+            ThreadActor::register(registry, script_sender.clone(), Some(name.clone()));
 
-        let watcher_actor = WatcherActor::new(
+        let watcher_name = WatcherActor::register(
             registry,
             name.clone(),
             SessionContext::new(SessionContextType::BrowserElement),
@@ -251,8 +246,8 @@ impl BrowsingContextActor {
         let mut script_chans = FxHashMap::default();
         script_chans.insert(pipeline_id, script_sender);
 
-        let target = BrowsingContextActor {
-            name,
+        let actor = BrowsingContextActor {
+            name: name.clone(),
             script_chans: AtomicRefCell::new(script_chans),
             title: AtomicRefCell::new(title),
             url: AtomicRefCell::new(url.into_string()),
@@ -260,26 +255,20 @@ impl BrowsingContextActor {
             active_outer_window_id: AtomicRefCell::new(outer_window_id),
             browser_id,
             browsing_context_id,
-            accessibility: accessibility_actor.name(),
+            accessibility_name,
             console_name,
-            css_properties_name: css_properties_actor.name(),
-            inspector,
-            reflow_name: reflow_actor.name(),
-            style_sheets_name: style_sheets_actor.name(),
-            _tab: tab_descriptor_actor.name(),
-            thread: thread.name(),
-            watcher_name: watcher_actor.name(),
+            css_properties_name,
+            inspector_name,
+            reflow_name,
+            style_sheets_name,
+            _tab: tab_descriptor_name,
+            thread_name,
+            watcher_name,
         };
 
-        registry.register(accessibility_actor);
-        registry.register(css_properties_actor);
-        registry.register(reflow_actor);
-        registry.register(style_sheets_actor);
-        registry.register(tab_descriptor_actor);
-        registry.register(thread);
-        registry.register(watcher_actor);
+        registry.register::<Self>(actor);
 
-        target
+        name
     }
 
     pub(crate) fn handle_new_global(
@@ -404,13 +393,13 @@ impl ActorEncode<BrowsingContextActorMsg> for BrowsingContextActor {
             browsing_context_id: self.browsing_context_id.value(),
             outer_window_id: self.outer_window_id().value(),
             is_top_level_target: true,
-            accessibility_actor: self.accessibility.clone(),
+            accessibility_actor: self.accessibility_name.clone(),
             console_actor: self.console_name.clone(),
             css_properties_actor: self.css_properties_name.clone(),
-            inspector_actor: self.inspector.clone(),
+            inspector_actor: self.inspector_name.clone(),
             reflow_actor: self.reflow_name.clone(),
             style_sheets_actor: self.style_sheets_name.clone(),
-            thread_actor: self.thread.clone(),
+            thread_actor: self.thread_name.clone(),
             target_type: TargetType::Frame,
         }
     }

components/devtools/actors/console.rs

@@ -10,27 +10,23 @@ use std::collections::HashMap;
 use std::sync::atomic::{AtomicBool, Ordering};
 
 use atomic_refcell::AtomicRefCell;
-use devtools_traits::DebuggerValue::{
-    self, BooleanValue, NullValue, NumberValue, ObjectValue, StringValue, VoidValue,
-};
 use devtools_traits::{
-    ConsoleArgument, ConsoleMessage, ConsoleMessageFields, DevtoolScriptControlMsg, PageError,
-    StackFrame, get_time_stamp,
+    ConsoleMessage, ConsoleMessageFields, DevtoolScriptControlMsg, PageError, StackFrame,
+    get_time_stamp,
 };
 use malloc_size_of_derive::MallocSizeOf;
 use serde::Serialize;
-use serde_json::{self, Map, Number, Value};
+use serde_json::{self, Map, Value};
 use servo_base::generic_channel::{self, GenericSender};
 use servo_base::id::TEST_PIPELINE_ID;
 use uuid::Uuid;
 
 use crate::actor::{Actor, ActorError, ActorRegistry};
 use crate::actors::browsing_context::BrowsingContextActor;
-use crate::actors::object::{ObjectActor, ObjectPropertyDescriptor};
-use crate::actors::worker::WorkerActor;
+use crate::actors::worker::WorkerTargetActor;
 use crate::protocol::{ClientRequest, DevtoolsConnection, JsonPacketStream};
 use crate::resource::{ResourceArrayType, ResourceAvailable};
-use crate::{EmptyReplyMsg, StreamId, UniqueId};
+use crate::{EmptyReplyMsg, StreamId, UniqueId, debugger_value_to_json};
 
 #[derive(Clone, Serialize, MallocSizeOf)]
 #[serde(rename_all = "camelCase")]
@@ -53,87 +49,13 @@ impl DevtoolsConsoleMessage {
             arguments: message
                 .arguments
                 .into_iter()
-                .map(|argument| console_argument_to_value(argument, registry))
+                .map(|argument| debugger_value_to_json(registry, argument))
                 .collect(),
             stacktrace: message.stacktrace,
         }
     }
 }
 
-fn console_argument_to_value(argument: ConsoleArgument, registry: &ActorRegistry) -> Value {
-    match argument {
-        ConsoleArgument::String(value) => Value::String(value),
-        ConsoleArgument::Integer(value) => Value::Number(value.into()),
-        ConsoleArgument::Number(value) => {
-            Number::from_f64(value).map(Value::from).unwrap_or_default()
-        },
-        ConsoleArgument::Boolean(value) => Value::Bool(value),
-        ConsoleArgument::Object(object) => {
-            // Create a new actor for the object.
-            // These are currently never cleaned up, and we make no attempt at re-using the same actor
-            // if the same object is logged repeatedly.
-            let actor = ObjectActor::register(registry, None, object.class.clone());
-
-            #[derive(Serialize)]
-            #[serde(rename_all = "camelCase")]
-            struct DevtoolsConsoleObjectArgument {
-                r#type: String,
-                actor: String,
-                class: String,
-                own_property_length: usize,
-                extensible: bool,
-                frozen: bool,
-                sealed: bool,
-                is_error: bool,
-                preview: DevtoolsConsoleObjectArgumentPreview,
-            }
-
-            #[derive(Serialize)]
-            #[serde(rename_all = "camelCase")]
-            struct DevtoolsConsoleObjectArgumentPreview {
-                kind: String,
-                own_properties: HashMap<String, ObjectPropertyDescriptor>,
-                own_properties_length: usize,
-            }
-
-            let own_properties: HashMap<String, ObjectPropertyDescriptor> = object
-                .own_properties
-                .into_iter()
-                .map(|property| {
-                    let property_descriptor = ObjectPropertyDescriptor {
-                        configurable: property.configurable,
-                        enumerable: property.enumerable,
-                        writable: property.writable,
-                        value: console_argument_to_value(property.value, registry),
-                    };
-
-                    (property.key, property_descriptor)
-                })
-                .collect();
-
-            let argument = DevtoolsConsoleObjectArgument {
-                r#type: "object".to_owned(),
-                actor,
-                class: object.class,
-                own_property_length: own_properties.len(),
-                extensible: true,
-                frozen: false,
-                sealed: false,
-                is_error: false,
-                preview: DevtoolsConsoleObjectArgumentPreview {
-                    kind: "Object".to_string(),
-                    own_properties_length: own_properties.len(),
-                    own_properties,
-                },
-            };
-
-            // to_value can fail if the implementation of Serialize fails or there are non-string map keys.
-            // Neither should be possible here
-            serde_json::to_value(argument).unwrap()
-        },
-    }
-}
-
 #[derive(Clone, Serialize, MallocSizeOf)]
 #[serde(rename_all = "camelCase")]
 struct DevtoolsPageError {
@@ -272,13 +194,15 @@ pub(crate) struct ConsoleActor {
 }
 
 impl ConsoleActor {
-    pub fn new(name: String, root: Root) -> Self {
-        Self {
-            name,
+    pub fn register(registry: &ActorRegistry, name: String, root: Root) -> String {
+        let actor = Self {
+            name: name.clone(),
             root,
             cached_events: Default::default(),
             client_ready_to_receive_messages: false.into(),
-        }
+        };
+        registry.register(actor);
+        name
     }
 
     fn script_chan(&self, registry: &ActorRegistry) -> GenericSender<DevtoolScriptControlMsg> {
@@ -287,8 +211,8 @@ impl ConsoleActor {
                 .find::<BrowsingContextActor>(browsing_context_name)
                 .script_chan(),
             Root::DedicatedWorker(worker_name) => registry
-                .find::<WorkerActor>(worker_name)
-                .script_chan
+                .find::<WorkerTargetActor>(worker_name)
+                .script_sender
                 .clone(),
         }
     }
@@ -301,124 +225,7 @@ impl ConsoleActor {
                     .pipeline_id(),
             ),
             Root::DedicatedWorker(worker_name) => {
-                UniqueId::Worker(registry.find::<WorkerActor>(worker_name).worker_id)
-            },
-        }
-    }
-
-    // TODO: This should be handled with struct serialization instead of manually adding values to a map
-    fn value_to_json(value: DebuggerValue, registry: &ActorRegistry) -> Value {
-        let mut m = Map::new();
-        match value {
-            VoidValue => {
-                m.insert("type".to_owned(), Value::String("undefined".to_owned()));
-                Value::Object(m)
-            },
-            NullValue => {
-                m.insert("type".to_owned(), Value::String("null".to_owned()));
-                Value::Object(m)
-            },
-            BooleanValue(val) => Value::Bool(val),
-            NumberValue(val) => {
-                if val.is_nan() {
-                    m.insert("type".to_owned(), Value::String("NaN".to_owned()));
-                    Value::Object(m)
-                } else if val.is_infinite() {
-                    if val < 0. {
-                        m.insert("type".to_owned(), Value::String("-Infinity".to_owned()));
-                    } else {
-                        m.insert("type".to_owned(), Value::String("Infinity".to_owned()));
-                    }
-                    Value::Object(m)
-                } else if val == 0. && val.is_sign_negative() {
-                    m.insert("type".to_owned(), Value::String("-0".to_owned()));
-                    Value::Object(m)
-                } else {
-                    Value::Number(Number::from_f64(val).unwrap())
-                }
-            },
-            StringValue(s) => Value::String(s),
-            ObjectValue {
-                uuid,
-                class,
-                preview,
-            } => {
-                let properties = preview
-                    .clone()
-                    .and_then(|preview| preview.own_properties)
-                    .unwrap_or_default();
-                let actor = ObjectActor::register_with_properties(
-                    registry,
-                    Some(uuid),
-                    class.clone(),
-                    properties,
-                );
-
-                m.insert("type".to_owned(), Value::String("object".to_owned()));
-                m.insert("class".to_owned(), Value::String(class));
-                m.insert("actor".to_owned(), Value::String(actor));
-                m.insert("extensible".to_owned(), Value::Bool(true));
-                m.insert("frozen".to_owned(), Value::Bool(false));
-                m.insert("sealed".to_owned(), Value::Bool(false));
-
-                // Build preview
-                // <https://searchfox.org/firefox-main/source/devtools/server/actors/object/previewers.js#849>
-                let Some(preview) = preview else {
-                    return Value::Object(m);
-                };
-                let mut preview_map = Map::new();
-
-                if preview.kind == "ArrayLike" {
-                    if let Some(length) = preview.array_length {
-                        preview_map.insert("length".to_owned(), Value::Number(length.into()));
-                    }
-                } else {
-                    if let Some(ref props) = preview.own_properties {
-                        let mut own_props_map = Map::new();
-                        for prop in props {
-                            let descriptor =
-                                serde_json::to_value(ObjectPropertyDescriptor::from(prop)).unwrap();
-                            own_props_map.insert(prop.name.clone(), descriptor);
-                        }
-                        preview_map
-                            .insert("ownProperties".to_owned(), Value::Object(own_props_map));
-                    }
-
-                    if let Some(length) = preview.own_properties_length {
-                        preview_map.insert(
-                            "ownPropertiesLength".to_owned(),
-                            Value::Number(length.into()),
-                        );
-                        m.insert("ownPropertyLength".to_owned(), Value::Number(length.into()));
-                    }
-                }
-                preview_map.insert("kind".to_owned(), Value::String(preview.kind));
-
-                // Function-specific metadata
-                if let Some(function) = preview.function {
-                    if let Some(name) = function.name {
-                        m.insert("name".to_owned(), Value::String(name));
-                    }
-                    if let Some(display_name) = function.display_name {
-                        m.insert("displayName".to_owned(), Value::String(display_name));
-                    }
-                    m.insert(
-                        "parameterNames".to_owned(),
-                        Value::Array(
-                            function
-                                .parameter_names
-                                .into_iter()
-                                .map(Value::String)
-                                .collect(),
-                        ),
-                    );
-                    m.insert("isAsync".to_owned(), Value::Bool(function.is_async));
-                    m.insert("isGenerator".to_owned(), Value::Bool(function.is_generator));
-                }
-
-                m.insert("preview".to_owned(), Value::Object(preview_map));
-
-                Value::Object(m)
+                UniqueId::Worker(registry.find::<WorkerTargetActor>(worker_name).worker_id)
             },
         }
     }
@@ -454,7 +261,7 @@ impl ConsoleActor {
         let reply = EvaluateJSReply {
             from: self.name(),
             input,
-            result: Self::value_to_json(eval_result.value, registry),
+            result: debugger_value_to_json(registry, eval_result.value),
             timestamp: get_time_stamp(),
             exception: Value::Null,
             exception_message: Value::Null,

components/devtools/actors/device.rs

@@ -74,8 +74,11 @@ impl Actor for DeviceActor {
 }
 
 impl DeviceActor {
-    pub fn new(name: String) -> DeviceActor {
-        DeviceActor { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = DeviceActor { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 
     pub fn description() -> ActorDescription {

components/devtools/actors/environment.rs

@@ -10,12 +10,12 @@ use serde::Serialize;
 use serde_json::Value;
 
 use crate::actor::{Actor, ActorEncode, ActorRegistry};
-use crate::actors::object::ObjectActorMsg;
+use crate::actors::object::{ObjectActorMsg, ObjectPropertyDescriptor};
 
 #[derive(Serialize)]
 struct EnvironmentBindings {
     arguments: Vec<Value>,
-    variables: HashMap<String, EnvironmentVariableDesc>,
+    variables: HashMap<String, ObjectPropertyDescriptor>,
 }
 
 #[derive(Serialize)]
@@ -24,14 +24,6 @@ struct EnvironmentFunction {
     display_name: String,
 }
 
-#[derive(Serialize)]
-struct EnvironmentVariableDesc {
-    value: String,
-    configurable: bool,
-    enumerable: bool,
-    writable: bool,
-}
-
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
 pub(crate) struct EnvironmentActorMsg {
@@ -110,15 +102,13 @@ impl ActorEncode<EnvironmentActorMsg> for EnvironmentActor {
                     .binding_variables
                     .clone()
                     .into_iter()
-                    .map(|(key, value)| {
+                    .map(|ref property_descriptor| {
                         (
-                            key,
-                            EnvironmentVariableDesc {
-                                value,
-                                configurable: false,
-                                enumerable: true,
-                                writable: false,
-                            },
+                            property_descriptor.name.clone(),
+                            ObjectPropertyDescriptor::from_property_descriptor(
+                                registry,
+                                property_descriptor,
+                            ),
                         )
                     })
                     .collect(),

components/devtools/actors/frame.rs

@@ -60,7 +60,7 @@ pub(crate) struct FrameActorMsg {
 pub(crate) struct FrameActor {
     name: String,
     object_actor: String,
-    source_actor: String,
+    source_name: String,
     frame_result: FrameInfo,
     current_offset: AtomicRefCell<(u32, u32)>,
 }
@@ -84,16 +84,16 @@ impl Actor for FrameActor {
                 let Some((tx, rx)) = channel() else {
                     return Err(ActorError::Internal);
                 };
-                let source = registry.find::<SourceActor>(&self.source_actor);
-                source
+                let source_actor = registry.find::<SourceActor>(&self.source_name);
+                source_actor
                     .script_sender
                     .send(DevtoolScriptControlMsg::GetEnvironment(self.name(), tx))
                     .map_err(|_| ActorError::Internal)?;
-                let environment = rx.recv().map_err(|_| ActorError::Internal)?;
+                let environment_name = rx.recv().map_err(|_| ActorError::Internal)?;
 
                 let msg = FrameEnvironmentReply {
                     from: self.name(),
-                    environment: registry.encode::<EnvironmentActor, _>(&environment),
+                    environment: registry.encode::<EnvironmentActor, _>(&environment_name),
                 };
                 // This reply has a `type` field but it doesn't need a followup,
                 // unlike most messages. We need to skip the validity check.
@@ -109,16 +109,16 @@ impl Actor for FrameActor {
 impl FrameActor {
     pub fn register(
         registry: &ActorRegistry,
-        source_actor: String,
+        source_name: String,
         frame_result: FrameInfo,
     ) -> String {
-        let object_actor = ObjectActor::register(registry, None, "Object".to_owned());
+        let object_name = ObjectActor::register(registry, None, "Object".to_owned(), None);
 
         let name = registry.new_name::<Self>();
         let actor = Self {
             name: name.clone(),
-            object_actor,
-            source_actor,
+            object_actor: object_name,
+            source_name,
             frame_result,
             current_offset: Default::default(),
         };
@@ -153,7 +153,7 @@ impl ActorEncode<FrameActorMsg> for FrameActor {
             oldest: self.frame_result.oldest,
             state,
             where_: FrameWhere {
-                actor: self.source_actor.clone(),
+                actor: self.source_name.clone(),
                 line,
                 column,
             },

components/devtools/actors/inspector.rs

@@ -4,7 +4,6 @@
 
 //! Liberally derived from the [Firefox JS implementation](http://mxr.mozilla.org/mozilla-central/source/toolkit/devtools/server/actors/inspector.js).
 
-use atomic_refcell::AtomicRefCell;
 use malloc_size_of_derive::MallocSizeOf;
 use serde::Serialize;
 use serde_json::{self, Map, Value};
@@ -17,11 +16,13 @@ use crate::protocol::ClientRequest;
 use crate::{ActorMsg, StreamId};
 
 pub mod accessibility;
+pub mod accessible_walker;
 pub mod css_properties;
 pub mod highlighter;
 pub mod layout;
 pub mod node;
 pub mod page_style;
+pub mod simulator;
 pub mod style_rule;
 pub mod walker;
 
@@ -55,7 +56,7 @@ pub(crate) struct InspectorActor {
     name: String,
     highlighter_name: String,
     page_style_name: String,
-    pub(crate) walker: String,
+    pub(crate) walker_name: String,
 }
 
 impl Actor for InspectorActor {
@@ -91,7 +92,7 @@ impl Actor for InspectorActor {
             "getWalker" => {
                 let msg = GetWalkerReply {
                     from: self.name(),
-                    walker: registry.encode::<WalkerActor, _>(&self.walker),
+                    walker: registry.encode::<WalkerActor, _>(&self.walker_name),
                 };
                 request.reply_final(&msg)?
             },
@@ -112,34 +113,22 @@ impl Actor for InspectorActor {
 
 impl InspectorActor {
     pub fn register(registry: &ActorRegistry, browsing_context_name: String) -> String {
-        let highlighter_actor = HighlighterActor {
-            name: registry.new_name::<HighlighterActor>(),
-            browsing_context_name: browsing_context_name.clone(),
-        };
+        let highlighter_name = HighlighterActor::register(registry, browsing_context_name.clone());
 
-        let page_style_actor = PageStyleActor {
-            name: registry.new_name::<PageStyleActor>(),
-        };
+        let page_style_name = PageStyleActor::register(registry);
 
-        let walker = WalkerActor {
-            name: registry.new_name::<WalkerActor>(),
-            mutations: AtomicRefCell::new(vec![]),
-            browsing_context_name,
-        };
+        let walker_name = WalkerActor::register(registry, browsing_context_name);
 
-        let actor = Self {
+        let inspector_actor = Self {
             name: registry.new_name::<InspectorActor>(),
-            highlighter_name: highlighter_actor.name(),
-            page_style_name: page_style_actor.name(),
-            walker: walker.name(),
+            highlighter_name,
+            page_style_name,
+            walker_name,
         };
-        let name = actor.name();
+        let inspector_name = inspector_actor.name();
 
-        registry.register(highlighter_actor);
-        registry.register(page_style_actor);
-        registry.register(walker);
-        registry.register(actor);
+        registry.register(inspector_actor);
 
-        name
+        inspector_name
     }
 }

components/devtools/actors/inspector/accessibility.rs

@@ -11,6 +11,8 @@ use serde_json::{Map, Value};
 
 use crate::StreamId;
 use crate::actor::{Actor, ActorError, ActorRegistry};
+use crate::actors::inspector::accessible_walker::AccessibleWalkerActor;
+use crate::actors::inspector::simulator::SimulatorActor;
 use crate::protocol::ClientRequest;
 
 #[derive(Serialize)]
@@ -90,14 +92,11 @@ impl Actor for AccessibilityActor {
                 request.reply_final(&msg)?
             },
             "getSimulator" => {
-                // TODO: Create actual simulator
-                let actor = registry.new_name::<SimulatorActor>();
-                registry.register(SimulatorActor {
-                    name: actor.clone(),
-                });
                 let msg = GetSimulatorReply {
                     from: self.name(),
-                    simulator: ActorMsg { actor },
+                    simulator: ActorMsg {
+                        actor: SimulatorActor::register(registry),
+                    },
                 };
                 request.reply_final(&msg)?
             },
@@ -111,14 +110,11 @@ impl Actor for AccessibilityActor {
                 request.reply_final(&msg)?
             },
             "getWalker" => {
-                // TODO: Create actual accessible walker
-                let actor = registry.new_name::<AccessibleWalkerActor>();
-                registry.register(AccessibleWalkerActor {
-                    name: actor.clone(),
-                });
                 let msg = GetWalkerReply {
                     from: self.name(),
-                    walker: ActorMsg { actor },
+                    walker: ActorMsg {
+                        actor: AccessibleWalkerActor::register(registry),
+                    },
                 };
                 request.reply_final(&msg)?
             },
@@ -129,29 +125,10 @@ impl Actor for AccessibilityActor {
 }
 
 impl AccessibilityActor {
-    pub fn new(name: String) -> Self {
-        Self { name }
-    }
-}
-
-#[derive(MallocSizeOf)]
-pub(crate) struct SimulatorActor {
-    name: String,
-}
-
-impl Actor for SimulatorActor {
-    fn name(&self) -> String {
-        self.name.clone()
-    }
-}
-
-#[derive(MallocSizeOf)]
-pub(crate) struct AccessibleWalkerActor {
-    name: String,
-}
-
-impl Actor for AccessibleWalkerActor {
-    fn name(&self) -> String {
-        self.name.clone()
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 }

components/devtools/actors/inspector/accessible_walker.rs

@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use malloc_size_of_derive::MallocSizeOf;
+
+use crate::actor::{Actor, ActorRegistry};
+
+#[derive(MallocSizeOf)]
+pub(crate) struct AccessibleWalkerActor {
+    name: String,
+}
+
+impl AccessibleWalkerActor {
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
+    }
+}
+
+impl Actor for AccessibleWalkerActor {
+    fn name(&self) -> String {
+        self.name.clone()
+    }
+}

components/devtools/actors/inspector/css_properties.rs

@@ -57,7 +57,16 @@ impl Actor for CssPropertiesActor {
 }
 
 impl CssPropertiesActor {
-    pub fn new(name: String, properties: HashMap<String, CssDatabaseProperty>) -> Self {
-        Self { name, properties }
+    pub fn register(
+        registry: &ActorRegistry,
+        properties: HashMap<String, CssDatabaseProperty>,
+    ) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
+            properties,
+        };
+        registry.register::<Self>(actor);
+        name
     }
 }

components/devtools/actors/inspector/highlighter.rs

@@ -97,12 +97,22 @@ impl Actor for HighlighterActor {
 }
 
 impl HighlighterActor {
+    pub fn register(registry: &ActorRegistry, browsing_context_name: String) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
+            browsing_context_name,
+        };
+        registry.register::<Self>(actor);
+        name
+    }
+
     fn instruct_script_thread_to_highlight_node(
         &self,
-        node_actor: Option<String>,
+        node_name: Option<String>,
         registry: &ActorRegistry,
     ) {
-        let node_id = node_actor.map(|node_actor| registry.actor_to_script(node_actor));
+        let node_id = node_name.map(|node_name| registry.actor_to_script(node_name));
         let browsing_context_actor =
             registry.find::<BrowsingContextActor>(&self.browsing_context_name);
         browsing_context_actor

components/devtools/actors/inspector/layout.rs

@@ -74,8 +74,11 @@ impl Actor for LayoutInspectorActor {
 }
 
 impl LayoutInspectorActor {
-    pub fn new(name: String) -> Self {
-        Self { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 }
 

components/devtools/actors/inspector/node.rs

@@ -9,7 +9,8 @@ use std::collections::HashMap;
 
 use atomic_refcell::AtomicRefCell;
 use devtools_traits::{
-    AttrModification, DevtoolScriptControlMsg, EventListenerInfo, NodeInfo, ShadowRootMode,
+    AttrModification, DevtoolScriptControlMsg, EventListenerInfo, MatchedRule, NodeInfo,
+    ShadowRootMode,
 };
 use malloc_size_of_derive::MallocSizeOf;
 use serde::Serialize;
@@ -132,7 +133,7 @@ pub(crate) struct NodeActor {
     pub script_chan: GenericSender<DevtoolScriptControlMsg>,
     pub pipeline: PipelineId,
     pub walker: String,
-    pub style_rules: AtomicRefCell<HashMap<(String, usize), String>>,
+    pub style_rules: AtomicRefCell<HashMap<MatchedRule, String>>,
 }
 
 impl Actor for NodeActor {
@@ -257,6 +258,30 @@ impl Actor for NodeActor {
     }
 }
 
+impl NodeActor {
+    pub fn register(
+        registry: &ActorRegistry,
+        script_id: String,
+        script_chan: GenericSender<DevtoolScriptControlMsg>,
+        pipeline: PipelineId,
+        walker: String,
+    ) -> String {
+        let name = registry.new_name::<Self>();
+
+        registry.register_script_actor(script_id, name.clone());
+
+        let actor = Self {
+            name: name.clone(),
+            script_chan,
+            pipeline,
+            walker,
+            style_rules: AtomicRefCell::new(HashMap::new()),
+        };
+
+        registry.register(actor);
+        name
+    }
+}
 pub trait NodeInfoToProtocol {
     fn encode(
         self,
@@ -277,18 +302,13 @@ impl NodeInfoToProtocol for NodeInfo {
     ) -> NodeActorMsg {
         let get_or_register_node_actor = |id: &str| {
             if !registry.script_actor_registered(id.to_string()) {
-                let name = registry.new_name::<NodeActor>();
-                registry.register_script_actor(id.to_string(), name.clone());
-
-                let node_actor = NodeActor {
-                    name: name.clone(),
-                    script_chan: script_chan.clone(),
+                NodeActor::register(
+                    registry,
+                    id.to_string(),
+                    script_chan.clone(),
                     pipeline,
-                    walker: walker.clone(),
-                    style_rules: AtomicRefCell::new(HashMap::new()),
-                };
-                registry.register(node_actor);
-                name
+                    walker.clone(),
+                )
             } else {
                 registry.script_to_actor(id.to_string())
             }

components/devtools/actors/inspector/page_style.rs

@@ -6,11 +6,10 @@
 //! properties applied, including the attributes and layout of each element.
 
 use std::collections::HashMap;
-use std::collections::hash_map::Entry;
 use std::iter::once;
 
 use devtools_traits::DevtoolScriptControlMsg::{GetLayout, GetSelectors};
-use devtools_traits::{AutoMargins, ComputedNodeLayout};
+use devtools_traits::{AutoMargins, ComputedNodeLayout, MatchedRule};
 use malloc_size_of_derive::MallocSizeOf;
 use serde::Serialize;
 use serde_json::{self, Map, Value};
@@ -130,33 +129,40 @@ impl Actor for PageStyleActor {
 }
 
 impl PageStyleActor {
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
+    }
+
     fn get_applied(
         &self,
         request: ClientRequest,
         msg: &Map<String, Value>,
         registry: &ActorRegistry,
     ) -> Result<(), ActorError> {
-        let target = msg
+        let node_name = msg
             .get("node")
             .ok_or(ActorError::MissingParameter)?
             .as_str()
             .ok_or(ActorError::BadParameterType)?;
-        let node = registry.find::<NodeActor>(target);
-        let walker = registry.find::<WalkerActor>(&node.walker);
+        let node_actor = registry.find::<NodeActor>(node_name);
+        let walker = registry.find::<WalkerActor>(&node_actor.walker);
         let browsing_context_actor = walker.browsing_context_actor(registry);
         let entries: Vec<_> = find_child(
-            &node.script_chan,
-            node.pipeline,
-            target,
+            &node_actor.script_chan,
+            node_actor.pipeline,
+            node_name,
             registry,
             &walker.root(registry)?.actor,
             vec![],
-            |msg| msg.actor == target,
+            |msg| msg.actor == node_name,
         )
         .unwrap_or_default()
         .into_iter()
         .flat_map(|node| {
-            let inherited = (node.actor != target).then(|| node.actor.clone());
+            let inherited = (node.actor != node_name).then(|| node.actor.clone());
             let node_actor = registry.find::<NodeActor>(&node.actor);
 
             // Get the css selectors that match this node present in the currently active stylesheets.
@@ -177,28 +183,33 @@ impl PageStyleActor {
             // For each selector (plus an empty one that represents the style attribute)
             // get all of the rules associated with it.
 
-            once(("".into(), usize::MAX))
-                .chain(selectors)
-                .filter_map(move |selector| {
-                    let rule = match node_actor.style_rules.borrow_mut().entry(selector) {
-                        Entry::Vacant(e) => {
-                            let name = registry.new_name::<StyleRuleActor>();
-                            let actor = StyleRuleActor::new(
-                                name.clone(),
-                                node_actor.name(),
-                                (!e.key().0.is_empty()).then_some(e.key().clone()),
-                            );
-                            let rule = actor.applied(registry)?;
+            let style_attribute_rule = MatchedRule {
+                selector: "".into(),
+                stylesheet_index: usize::MAX,
+                block_id: 0,
+                ancestor_data: vec![],
+            };
 
-                            registry.register(actor);
-                            e.insert(name);
-                            rule
-                        },
-                        Entry::Occupied(e) => {
-                            let actor = registry.find::<StyleRuleActor>(e.get());
-                            actor.applied(registry)?
-                        },
-                    };
+            once(style_attribute_rule)
+                .chain(selectors)
+                .filter_map(move |matched_rule| {
+                    let style_rule_name = node_actor
+                        .style_rules
+                        .borrow_mut()
+                        .entry(matched_rule.clone())
+                        .or_insert_with(|| {
+                            StyleRuleActor::register(
+                                registry,
+                                node_actor.name(),
+                                (matched_rule.stylesheet_index != usize::MAX)
+                                    .then_some(matched_rule.clone()),
+                            )
+                        })
+                        .clone();
+
+                    let rule = registry
+                        .find::<StyleRuleActor>(&style_rule_name)
+                        .applied(registry)?;
                     if inherited.is_some() && rule.declarations.is_empty() {
                         return None;
                     }
@@ -226,31 +237,30 @@ impl PageStyleActor {
         msg: &Map<String, Value>,
         registry: &ActorRegistry,
     ) -> Result<(), ActorError> {
-        let target = msg
+        let node_name = msg
             .get("node")
             .ok_or(ActorError::MissingParameter)?
             .as_str()
             .ok_or(ActorError::BadParameterType)?;
-        let node_actor = registry.find::<NodeActor>(target);
-        let computed = (|| match node_actor
+        let node_actor = registry.find::<NodeActor>(node_name);
+        let style_attribute_rule = devtools_traits::MatchedRule {
+            selector: "".into(),
+            stylesheet_index: usize::MAX,
+            block_id: 0,
+            ancestor_data: vec![],
+        };
+
+        let style_rule_name = node_actor
             .style_rules
             .borrow_mut()
-            .entry(("".into(), usize::MAX))
-        {
-            Entry::Vacant(e) => {
-                let name = registry.new_name::<StyleRuleActor>();
-                let actor = StyleRuleActor::new(name.clone(), target.into(), None);
-                let computed = actor.computed(registry)?;
-                registry.register(actor);
-                e.insert(name);
-                Some(computed)
-            },
-            Entry::Occupied(e) => {
-                let actor = registry.find::<StyleRuleActor>(e.get());
-                Some(actor.computed(registry)?)
-            },
-        })()
-        .unwrap_or_default();
+            .entry(style_attribute_rule)
+            .or_insert_with(|| StyleRuleActor::register(registry, node_name.into(), None))
+            .clone();
+        let computed = registry
+            .find::<StyleRuleActor>(&style_rule_name)
+            .computed(registry)
+            .unwrap_or_default();
+
         let msg = GetComputedReply {
             computed,
             from: self.name(),
@@ -264,20 +274,20 @@ impl PageStyleActor {
         msg: &Map<String, Value>,
         registry: &ActorRegistry,
     ) -> Result<(), ActorError> {
-        let target = msg
+        let node_name = msg
             .get("node")
             .ok_or(ActorError::MissingParameter)?
             .as_str()
             .ok_or(ActorError::BadParameterType)?;
-        let node = registry.find::<NodeActor>(target);
-        let walker = registry.find::<WalkerActor>(&node.walker);
+        let node_actor = registry.find::<NodeActor>(node_name);
+        let walker = registry.find::<WalkerActor>(&node_actor.walker);
         let browsing_context_actor = walker.browsing_context_actor(registry);
         let (tx, rx) = generic_channel::channel().ok_or(ActorError::Internal)?;
         browsing_context_actor
             .script_chan()
             .send(GetLayout(
                 browsing_context_actor.pipeline_id(),
-                registry.actor_to_script(target.to_owned()),
+                registry.actor_to_script(node_name.to_owned()),
                 tx,
             ))
             .map_err(|_| ActorError::Internal)?;

components/devtools/actors/inspector/simulator.rs

@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use malloc_size_of_derive::MallocSizeOf;
+
+use crate::actor::{Actor, ActorRegistry};
+
+#[derive(MallocSizeOf)]
+pub(crate) struct SimulatorActor {
+    name: String,
+}
+
+impl SimulatorActor {
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
+    }
+}
+
+impl Actor for SimulatorActor {
+    fn name(&self) -> String {
+        self.name.clone()
+    }
+}

components/devtools/actors/inspector/style_rule.rs

@@ -11,6 +11,7 @@ use std::collections::HashMap;
 use devtools_traits::DevtoolScriptControlMsg::{
     GetAttributeStyle, GetComputedStyle, GetDocumentElement, GetStylesheetStyle, ModifyRule,
 };
+use devtools_traits::{AncestorData, MatchedRule};
 use malloc_size_of_derive::MallocSizeOf;
 use serde::Serialize;
 use serde_json::{Map, Value};
@@ -28,7 +29,7 @@ const ELEMENT_STYLE_TYPE: u32 = 100;
 #[serde(rename_all = "camelCase")]
 pub(crate) struct AppliedRule {
     actor: String,
-    ancestor_data: Vec<()>,
+    ancestor_data: Vec<AncestorData>,
     authored_text: String,
     css_text: String,
     pub declarations: Vec<AppliedDeclaration>,
@@ -82,8 +83,8 @@ pub(crate) struct StyleRuleActorMsg {
 #[derive(MallocSizeOf)]
 pub(crate) struct StyleRuleActor {
     name: String,
-    node: String,
-    selector: Option<(String, usize)>,
+    node_name: String,
+    selector: Option<MatchedRule>,
 }
 
 impl Actor for StyleRuleActor {
@@ -121,14 +122,14 @@ impl Actor for StyleRuleActor {
                     .collect();
 
                 // Query the rule modification
-                let node = registry.find::<NodeActor>(&self.node);
-                let walker = registry.find::<WalkerActor>(&node.walker);
+                let node_actor = registry.find::<NodeActor>(&self.node_name);
+                let walker = registry.find::<WalkerActor>(&node_actor.walker);
                 let browsing_context_actor = walker.browsing_context_actor(registry);
                 browsing_context_actor
                     .script_chan()
                     .send(ModifyRule(
                         browsing_context_actor.pipeline_id(),
-                        registry.actor_to_script(self.node.clone()),
+                        registry.actor_to_script(self.node_name.clone()),
                         modifications,
                     ))
                     .map_err(|_| ActorError::Internal)?;
@@ -142,17 +143,24 @@ impl Actor for StyleRuleActor {
 }
 
 impl StyleRuleActor {
-    pub fn new(name: String, node: String, selector: Option<(String, usize)>) -> Self {
-        Self {
-            name,
-            node,
+    pub fn register(
+        registry: &ActorRegistry,
+        node: String,
+        selector: Option<MatchedRule>,
+    ) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
+            node_name: node,
             selector,
-        }
+        };
+        registry.register::<Self>(actor);
+        name
     }
 
     pub fn applied(&self, registry: &ActorRegistry) -> Option<AppliedRule> {
-        let node = registry.find::<NodeActor>(&self.node);
-        let walker = registry.find::<WalkerActor>(&node.walker);
+        let node_actor = registry.find::<NodeActor>(&self.node_name);
+        let walker = registry.find::<WalkerActor>(&node_actor.walker);
         let browsing_context_actor = walker.browsing_context_actor(registry);
 
         let (document_sender, document_receiver) = generic_channel::channel()?;
@@ -169,19 +177,15 @@ impl StyleRuleActor {
         // not, this represents the style attribute.
         let (style_sender, style_receiver) = generic_channel::channel()?;
         let req = match &self.selector {
-            Some(selector) => {
-                let (selector, stylesheet) = selector.clone();
-                GetStylesheetStyle(
-                    browsing_context_actor.pipeline_id(),
-                    registry.actor_to_script(self.node.clone()),
-                    selector,
-                    stylesheet,
-                    style_sender,
-                )
-            },
+            Some(matched_rule) => GetStylesheetStyle(
+                browsing_context_actor.pipeline_id(),
+                registry.actor_to_script(self.node_name.clone()),
+                matched_rule.clone(),
+                style_sender,
+            ),
             None => GetAttributeStyle(
                 browsing_context_actor.pipeline_id(),
-                registry.actor_to_script(self.node.clone()),
+                registry.actor_to_script(self.node_name.clone()),
                 style_sender,
             ),
         };
@@ -190,7 +194,11 @@ impl StyleRuleActor {
 
         Some(AppliedRule {
             actor: self.name(),
-            ancestor_data: vec![], // TODO: Fill with hierarchy
+            ancestor_data: self
+                .selector
+                .as_ref()
+                .map(|r| r.ancestor_data.clone())
+                .unwrap_or_default(),
             authored_text: "".into(),
             css_text: "".into(), // TODO: Specify the css text
             declarations: style
@@ -210,7 +218,7 @@ impl StyleRuleActor {
                 })
                 .collect(),
             href: node.base_uri,
-            selectors: self.selector.iter().map(|(s, _)| s).cloned().collect(),
+            selectors: self.selector.iter().map(|r| r.selector.clone()).collect(),
             selectors_specificity: self.selector.iter().map(|_| 1).collect(),
             type_: ELEMENT_STYLE_TYPE,
             traits: StyleRuleActorTraits {
@@ -223,8 +231,8 @@ impl StyleRuleActor {
         &self,
         registry: &ActorRegistry,
     ) -> Option<HashMap<String, ComputedDeclaration>> {
-        let node = registry.find::<NodeActor>(&self.node);
-        let walker = registry.find::<WalkerActor>(&node.walker);
+        let node_actor = registry.find::<NodeActor>(&self.node_name);
+        let walker = registry.find::<WalkerActor>(&node_actor.walker);
         let browsing_context_actor = walker.browsing_context_actor(registry);
 
         let (style_sender, style_receiver) = generic_channel::channel()?;
@@ -232,7 +240,7 @@ impl StyleRuleActor {
             .script_chan()
             .send(GetComputedStyle(
                 browsing_context_actor.pipeline_id(),
-                registry.actor_to_script(self.node.clone()),
+                registry.actor_to_script(self.node_name.clone()),
                 style_sender,
             ))
             .ok()?;

components/devtools/actors/inspector/walker.rs

@@ -213,14 +213,14 @@ impl Actor for WalkerActor {
             },
             "getLayoutInspector" => {
                 // TODO: Create actual layout inspector actor
+                let layout_inspector_name = LayoutInspectorActor::register(registry);
                 let layout_inspector_actor =
-                    LayoutInspectorActor::new(registry.new_name::<LayoutInspectorActor>());
+                    registry.find::<LayoutInspectorActor>(&layout_inspector_name);
 
                 let msg = GetLayoutInspectorReply {
                     from: self.name(),
                     actor: layout_inspector_actor.encode(registry),
                 };
-                registry.register(layout_inspector_actor);
                 request.reply_final(&msg)?
             },
             "getMutations" => self.handle_get_mutations(request, registry)?,
@@ -237,7 +237,7 @@ impl Actor for WalkerActor {
                     .ok_or(ActorError::MissingParameter)?
                     .as_str()
                     .ok_or(ActorError::BadParameterType)?;
-                let node = msg
+                let node_name = msg
                     .get("node")
                     .ok_or(ActorError::MissingParameter)?
                     .as_str()
@@ -247,7 +247,7 @@ impl Actor for WalkerActor {
                     browsing_context_actor.pipeline_id(),
                     &self.name,
                     registry,
-                    node,
+                    node_name,
                     vec![],
                     |msg| msg.display_name == selector,
                 )
@@ -280,6 +280,17 @@ impl Actor for WalkerActor {
 }
 
 impl WalkerActor {
+    pub fn register(registry: &ActorRegistry, browsing_context_name: String) -> String {
+        let name = registry.new_name::<WalkerActor>();
+        let actor = WalkerActor {
+            name: name.clone(),
+            mutations: AtomicRefCell::new(vec![]),
+            browsing_context_name,
+        };
+        registry.register::<Self>(actor);
+        name
+    }
+
     pub(crate) fn browsing_context_actor(
         &self,
         registry: &ActorRegistry,
@@ -378,7 +389,7 @@ pub fn find_child(
     pipeline: PipelineId,
     name: &str,
     registry: &ActorRegistry,
-    node: &str,
+    node_name: &str,
     mut hierarchy: Vec<NodeActorMsg>,
     compare_fn: impl Fn(&NodeActorMsg) -> bool + Clone,
 ) -> Result<Vec<NodeActorMsg>, Vec<NodeActorMsg>> {
@@ -386,7 +397,7 @@ pub fn find_child(
     script_chan
         .send(GetChildren(
             pipeline,
-            registry.actor_to_script(node.into()),
+            registry.actor_to_script(node_name.into()),
             tx,
         ))
         .unwrap();

components/devtools/actors/long_string.rs

@@ -73,9 +73,14 @@ impl Actor for LongStringActor {
 }
 
 impl LongStringActor {
-    pub fn new(registry: &ActorRegistry, full_string: String) -> Self {
+    pub fn register(registry: &ActorRegistry, full_string: String) -> String {
         let name = registry.new_name::<Self>();
-        LongStringActor { name, full_string }
+        let actor = Self {
+            name: name.clone(),
+            full_string,
+        };
+        registry.register::<Self>(actor);
+        name
     }
 
     pub fn long_string_obj(&self) -> LongStringObj {

components/devtools/actors/network_event.rs

@@ -468,9 +468,10 @@ impl Actor for NetworkEventActor {
                     let (encoding, text) = if mime_type.is_some() {
                         // Queue a LongStringActor for this body
                         let body_string = String::from_utf8_lossy(body).to_string();
-                        let long_string = LongStringActor::new(registry, body_string);
-                        let value = long_string.long_string_obj();
-                        registry.register(long_string);
+                        let long_string_name = LongStringActor::register(registry, body_string);
+                        let value = registry
+                            .find::<LongStringActor>(&long_string_name)
+                            .long_string_obj();
                         (None, serde_json::to_value(value).unwrap())
                     } else {
                         let b64 = STANDARD.encode(&body.0);
@@ -535,13 +536,16 @@ impl Actor for NetworkEventActor {
 }
 
 impl NetworkEventActor {
-    pub fn new(name: String, resource_id: u64, watcher_name: String) -> NetworkEventActor {
-        NetworkEventActor {
-            name,
+    pub fn register(registry: &ActorRegistry, resource_id: u64, watcher_name: String) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = NetworkEventActor {
+            name: name.clone(),
             resource_id,
             watcher_name,
             ..Default::default()
-        }
+        };
+        registry.register::<Self>(actor);
+        name
     }
 
     pub fn add_request(&self, request: HttpRequest) {

components/devtools/actors/object.rs

@@ -2,21 +2,18 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use std::collections::HashMap;
+
 use devtools_traits::{DebuggerValue, PropertyDescriptor};
 use malloc_size_of_derive::MallocSizeOf;
 use serde::Serialize;
-use serde_json::{Map, Number, Value};
+use serde_json::{Map, Value};
 
-use crate::StreamId;
 use crate::actor::{Actor, ActorEncode, ActorError, ActorRegistry};
 use crate::actors::property_iterator::PropertyIteratorActor;
+use crate::actors::symbol_iterator::SymbolIteratorActor;
 use crate::protocol::ClientRequest;
-
-#[derive(Serialize)]
-pub(crate) struct ObjectPreview {
-    kind: String,
-    url: String,
-}
+use crate::{StreamId, debugger_value_to_json};
 
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
@@ -45,6 +42,37 @@ struct PrototypeReply {
     prototype: ObjectActorMsg,
 }
 
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct ObjectPreview {
+    pub kind: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub own_properties: Option<HashMap<String, ObjectPropertyDescriptor>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub own_properties_length: Option<u32>,
+    #[serde(flatten)]
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub function: Option<FunctionPreview>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub length: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub items: Option<Vec<Value>>,
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct FunctionPreview {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub name: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub display_name: Option<String>,
+    pub parameter_names: Vec<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub is_async: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub is_generator: Option<bool>,
+}
+
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
 pub(crate) struct ObjectActorMsg {
@@ -52,78 +80,46 @@ pub(crate) struct ObjectActorMsg {
     #[serde(rename = "type")]
     type_: String,
     class: String,
-    own_property_length: i32,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    own_property_length: Option<u32>,
     extensible: bool,
     frozen: bool,
     sealed: bool,
-    is_error: bool,
-    preview: ObjectPreview,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    preview: Option<ObjectPreview>,
 }
 
 #[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
 pub(crate) struct ObjectPropertyDescriptor {
+    pub value: Value,
     pub configurable: bool,
     pub enumerable: bool,
     pub writable: bool,
-    pub value: Value,
+    pub is_accessor: bool,
 }
 
-impl From<&PropertyDescriptor> for ObjectPropertyDescriptor {
-    fn from(prop: &PropertyDescriptor) -> Self {
+impl ObjectPropertyDescriptor {
+    pub(crate) fn from_property_descriptor(
+        registry: &ActorRegistry,
+        prop: &PropertyDescriptor,
+    ) -> Self {
         Self {
+            value: debugger_value_to_json(registry, prop.value.clone()),
             configurable: prop.configurable,
             enumerable: prop.enumerable,
             writable: prop.writable,
-            value: debugger_value_to_json(&prop.value, &prop.name),
+            is_accessor: prop.is_accessor,
         }
     }
 }
 
-/// <https://searchfox.org/mozilla-central/source/devtools/server/actors/object/utils.js#148>
-fn debugger_value_to_json(value: &DebuggerValue, name: &str) -> Value {
-    match value {
-        DebuggerValue::VoidValue => {
-            let mut v = Map::new();
-            v.insert("type".to_owned(), Value::String("undefined".to_owned()));
-            Value::Object(v)
-        },
-        DebuggerValue::NullValue => Value::Null,
-        DebuggerValue::BooleanValue(boolean) => Value::Bool(*boolean),
-        DebuggerValue::NumberValue(num) => {
-            if num.is_nan() {
-                let mut v = Map::new();
-                v.insert("type".to_owned(), Value::String("NaN".to_owned()));
-                Value::Object(v)
-            } else if num.is_infinite() {
-                let mut v = Map::new();
-                let type_str = if num.is_sign_positive() {
-                    "Infinity"
-                } else {
-                    "-Infinity"
-                };
-                v.insert("type".to_owned(), Value::String(type_str.to_owned()));
-                Value::Object(v)
-            } else {
-                Value::Number(Number::from_f64(*num).unwrap_or(Number::from(0)))
-            }
-        },
-        DebuggerValue::StringValue(str) => Value::String(str.clone()),
-        DebuggerValue::ObjectValue { class, .. } => {
-            let mut v = Map::new();
-            v.insert("type".to_owned(), Value::String("object".to_owned()));
-            v.insert("class".to_owned(), Value::String(class.clone()));
-            v.insert("name".to_owned(), Value::String(name.into()));
-            Value::Object(v)
-        },
-    }
-}
-
 #[derive(MallocSizeOf)]
 pub(crate) struct ObjectActor {
     name: String,
     _uuid: Option<String>,
     class: String,
-    properties: Vec<PropertyDescriptor>,
+    preview: Option<devtools_traits::ObjectPreview>,
 }
 
 impl Actor for ObjectActor {
@@ -142,11 +138,49 @@ impl Actor for ObjectActor {
     ) -> Result<(), ActorError> {
         match msg_type {
             "enumProperties" => {
-                let property_iterator_name =
-                    PropertyIteratorActor::register(registry, self.properties.clone());
-                let property_iterator =
+                let properties = self.preview.as_ref().map_or_else(Vec::new, |preview| {
+                    if preview.kind == "ArrayLike" {
+                        // For arrays, convert items to indexed properties
+                        // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyDescriptor#description>
+                        let mut props: Vec<PropertyDescriptor> = preview
+                            .items
+                            .as_ref()
+                            .map(|items| {
+                                items
+                                    .iter()
+                                    .enumerate()
+                                    .map(|(index, value)| PropertyDescriptor {
+                                        name: index.to_string(),
+                                        value: value.clone(),
+                                        configurable: true,
+                                        enumerable: true,
+                                        writable: true,
+                                        is_accessor: false,
+                                    })
+                                    .collect()
+                            })
+                            .unwrap_or_default();
+                        // Add length property
+                        if let Some(length) = preview.array_length {
+                            // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/length#value>
+                            props.push(PropertyDescriptor {
+                                name: "length".to_string(),
+                                value: DebuggerValue::NumberValue(length as f64),
+                                configurable: false,
+                                enumerable: false,
+                                writable: true,
+                                is_accessor: false,
+                            });
+                        }
+                        props
+                    } else {
+                        preview.own_properties.clone().unwrap_or_default()
+                    }
+                });
+                let property_iterator_name = PropertyIteratorActor::register(registry, properties);
+                let property_iterator_actor =
                     registry.find::<PropertyIteratorActor>(&property_iterator_name);
-                let count = property_iterator.count();
+                let count = property_iterator_actor.count();
                 let msg = EnumReply {
                     from: self.name(),
                     iterator: EnumIterator {
@@ -160,18 +194,15 @@ impl Actor for ObjectActor {
             },
 
             "enumSymbols" => {
-                let symbol_iterator = SymbolIteratorActor {
-                    name: registry.new_name::<SymbolIteratorActor>(),
-                };
+                let symbol_iterator_name = SymbolIteratorActor::register(registry);
                 let msg = EnumReply {
                     from: self.name(),
                     iterator: EnumIterator {
-                        actor: symbol_iterator.name(),
+                        actor: symbol_iterator_name,
                         type_: EnumIteratorType::SymbolIterator,
                         count: 0,
                     },
                 };
-                registry.register(symbol_iterator);
                 request.reply_final(&msg)?
             },
 
@@ -190,15 +221,11 @@ impl Actor for ObjectActor {
 }
 
 impl ObjectActor {
-    pub fn register(registry: &ActorRegistry, uuid: Option<String>, class: String) -> String {
-        Self::register_with_properties(registry, uuid, class, Vec::new())
-    }
-
-    pub fn register_with_properties(
+    pub fn register(
         registry: &ActorRegistry,
         uuid: Option<String>,
         class: String,
-        properties: Vec<PropertyDescriptor>,
+        preview: Option<devtools_traits::ObjectPreview>,
     ) -> String {
         let Some(uuid) = uuid else {
             let name = registry.new_name::<Self>();
@@ -206,7 +233,7 @@ impl ObjectActor {
                 name: name.clone(),
                 _uuid: None,
                 class,
-                properties,
+                preview,
             };
             registry.register(actor);
             return name;
@@ -217,7 +244,7 @@ impl ObjectActor {
                 name: name.clone(),
                 _uuid: Some(uuid.clone()),
                 class,
-                properties,
+                preview,
             };
 
             registry.register_script_actor(uuid, name.clone());
@@ -231,31 +258,58 @@ impl ObjectActor {
 }
 
 impl ActorEncode<ObjectActorMsg> for ObjectActor {
-    fn encode(&self, _: &ActorRegistry) -> ObjectActorMsg {
-        ObjectActorMsg {
+    fn encode(&self, registry: &ActorRegistry) -> ObjectActorMsg {
+        let mut msg = ObjectActorMsg {
             actor: self.name(),
             type_: "object".into(),
             class: self.class.clone(),
-            own_property_length: self.properties.len() as i32,
             extensible: true,
             frozen: false,
             sealed: false,
-            is_error: false,
-            preview: ObjectPreview {
-                kind: "ObjectWithURL".into(),
-                url: "".into(), // TODO: Use the correct url
-            },
-        }
-    }
-}
-
-#[derive(MallocSizeOf)]
-struct SymbolIteratorActor {
-    name: String,
-}
-
-impl Actor for SymbolIteratorActor {
-    fn name(&self) -> String {
-        self.name.clone()
+            preview: None,
+            own_property_length: None,
+        };
+
+        // Build preview
+        // <https://searchfox.org/firefox-main/source/devtools/server/actors/object/previewers.js#849>
+        let Some(preview) = self.preview.clone() else {
+            return msg;
+        };
+        msg.own_property_length = preview.own_properties_length;
+
+        let function = preview.function.map(|function| FunctionPreview {
+            name: function.name.clone(),
+            display_name: function.display_name.clone(),
+            parameter_names: function.parameter_names.clone(),
+            is_async: function.is_async,
+            is_generator: function.is_generator,
+        });
+
+        let preview = ObjectPreview {
+            kind: preview.kind.clone(),
+            own_properties: preview.own_properties.map(|own_properties| {
+                own_properties
+                    .iter()
+                    .map(|prop| {
+                        (
+                            prop.name.clone(),
+                            ObjectPropertyDescriptor::from_property_descriptor(registry, prop),
+                        )
+                    })
+                    .collect()
+            }),
+            own_properties_length: preview.own_properties_length,
+            function,
+            length: preview.array_length,
+            items: preview.items.map(|items| {
+                items
+                    .iter()
+                    .map(|item| debugger_value_to_json(registry, item.clone()))
+                    .collect()
+            }),
+        };
+
+        msg.preview = Some(preview);
+        msg
     }
 }

components/devtools/actors/pause.rs

@@ -4,13 +4,13 @@
 
 use malloc_size_of_derive::MallocSizeOf;
 
-use crate::actor::Actor;
+use crate::actor::{Actor, ActorRegistry};
 
 /// Referenced by `ThreadActor` when replying to `interupt` messages.
 /// <https://searchfox.org/firefox-main/source/devtools/server/actors/thread.js#1699>
 #[derive(MallocSizeOf)]
 pub(crate) struct PauseActor {
-    pub name: String,
+    name: String,
 }
 
 impl Actor for PauseActor {
@@ -18,3 +18,12 @@ impl Actor for PauseActor {
         self.name.clone()
     }
 }
+
+impl PauseActor {
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
+    }
+}

components/devtools/actors/performance.rs

@@ -98,8 +98,11 @@ impl Actor for PerformanceActor {
 }
 
 impl PerformanceActor {
-    pub fn new(name: String) -> PerformanceActor {
-        PerformanceActor { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = PerformanceActor { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 
     pub fn description() -> ActorDescription {

components/devtools/actors/preference.rs

@@ -17,8 +17,11 @@ pub(crate) struct PreferenceActor {
 }
 
 impl PreferenceActor {
-    pub fn new(name: String) -> Self {
-        Self { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 }
 

components/devtools/actors/process.rs

@@ -68,8 +68,11 @@ impl Actor for ProcessActor {
 }
 
 impl ProcessActor {
-    pub fn new(name: String) -> Self {
-        Self { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 }
 

components/devtools/actors/property_iterator.rs

@@ -51,7 +51,7 @@ impl Actor for PropertyIteratorActor {
     fn handle_message(
         &self,
         request: ClientRequest,
-        _registry: &ActorRegistry,
+        registry: &ActorRegistry,
         msg_type: &str,
         msg: &Map<String, Value>,
         _id: StreamId,
@@ -66,7 +66,10 @@ impl Actor for PropertyIteratorActor {
 
                 let mut own_properties = HashMap::new();
                 for prop in self.properties.iter().skip(start).take(count) {
-                    own_properties.insert(prop.name.clone(), ObjectPropertyDescriptor::from(prop));
+                    own_properties.insert(
+                        prop.name.clone(),
+                        ObjectPropertyDescriptor::from_property_descriptor(registry, prop),
+                    );
                 }
 
                 let reply = SliceReply {

components/devtools/actors/reflow.rs

@@ -47,7 +47,10 @@ impl Actor for ReflowActor {
 }
 
 impl ReflowActor {
-    pub fn new(name: String) -> Self {
-        Self { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 }

components/devtools/actors/root.rs

@@ -22,7 +22,7 @@ use crate::actors::performance::PerformanceActor;
 use crate::actors::preference::PreferenceActor;
 use crate::actors::process::{ProcessActor, ProcessActorMsg};
 use crate::actors::tab::{TabDescriptorActor, TabDescriptorActorMsg};
-use crate::actors::worker::{WorkerActor, WorkerActorMsg};
+use crate::actors::worker::{WorkerTargetActor, WorkerTargetActorMsg};
 use crate::protocol::{ActorDescription, ClientRequest};
 use crate::{EmptyReplyMsg, StreamId};
 
@@ -123,7 +123,7 @@ pub(crate) struct ProtocolDescriptionReply {
 #[derive(Serialize)]
 struct ListWorkersReply {
     from: String,
-    workers: Vec<WorkerActorMsg>,
+    workers: Vec<WorkerTargetActorMsg>,
 }
 
 #[derive(Serialize)]
@@ -248,12 +248,12 @@ impl Actor for RootActor {
                     .borrow()
                     .iter()
                     .map(|worker_name| {
-                        let worker = registry.find::<WorkerActor>(worker_name);
-                        let url = worker.url.to_string();
+                        let worker_actor = registry.find::<WorkerTargetActor>(worker_name);
+                        let url = worker_actor.url.to_string();
                         // Find correct scope url in the service worker
                         let scope = url.clone();
                         ServiceWorkerRegistrationMsg {
-                            actor: worker.name(),
+                            actor: worker_actor.name(),
                             scope,
                             url: url.clone(),
                             registration_state: "".to_string(),
@@ -263,11 +263,11 @@ impl Actor for RootActor {
                             installing_worker: None,
                             waiting_worker: None,
                             active_worker: Some(ServiceWorkerInfo {
-                                actor: worker.name(),
+                                actor: worker_actor.name(),
                                 url,
                                 state: 4, // activated
                                 state_text: "activated".to_string(),
-                                id: worker.worker_id.to_string(),
+                                id: worker_actor.worker_id.to_string(),
                                 fetch: false,
                                 traits: HashMap::new(),
                             }),
@@ -310,7 +310,7 @@ impl Actor for RootActor {
                         .workers
                         .borrow()
                         .iter()
-                        .map(|worker_name| registry.encode::<WorkerActor, _>(worker_name))
+                        .map(|worker_name| registry.encode::<WorkerTargetActor, _>(worker_name))
                         .collect(),
                 };
                 request.reply_final(&reply)?
@@ -347,28 +347,24 @@ impl RootActor {
     /// Registers the root actor and its global actors (those not associated with a specific target).
     pub fn register(registry: &mut ActorRegistry) {
         // Global actors
-        let device_actor = DeviceActor::new(registry.new_name::<DeviceActor>());
-        let perf = PerformanceActor::new(registry.new_name::<PerformanceActor>());
-        let preference_actor = PreferenceActor::new(registry.new_name::<PreferenceActor>());
+        let device_name = DeviceActor::register(registry);
+        let performance_name = PerformanceActor::register(registry);
+        let preference_name = PreferenceActor::register(registry);
 
         // Process descriptor
-        let process_actor = ProcessActor::new(registry.new_name::<ProcessActor>());
+        let process_name = ProcessActor::register(registry);
 
         // Root actor
         let root_actor = Self {
             global_actors: GlobalActors {
-                device_actor: device_actor.name(),
-                perf_actor: perf.name(),
-                preference_actor: preference_actor.name(),
+                device_actor: device_name,
+                perf_actor: performance_name,
+                preference_actor: preference_name,
             },
-            process_name: process_actor.name(),
+            process_name,
             ..Default::default()
         };
 
-        registry.register(perf);
-        registry.register(device_actor);
-        registry.register(process_actor);
-        registry.register(preference_actor);
         registry.register(root_actor);
     }
 

components/devtools/actors/source.rs

@@ -64,7 +64,7 @@ impl SourceManager {
         self.source_actor_names
             .borrow()
             .iter()
-            .map(|actor_name| registry.find::<SourceActor>(actor_name).source_form())
+            .map(|source_name| registry.find::<SourceActor>(source_name).source_form())
             .collect()
     }
 
@@ -73,10 +73,10 @@ impl SourceManager {
         registry: &ActorRegistry,
         source_url: &str,
     ) -> Option<DowncastableActorArc<SourceActor>> {
-        for name in self.source_actor_names.borrow().iter() {
-            let source = registry.find::<SourceActor>(name);
-            if source.url == ServoUrl::from_str(source_url).ok()? {
-                return Some(source);
+        for source_name in self.source_actor_names.borrow().iter() {
+            let source_actor = registry.find::<SourceActor>(source_name);
+            if source_actor.url == ServoUrl::from_str(source_url).ok()? {
+                return Some(source_actor);
             }
         }
         None
@@ -143,29 +143,8 @@ struct GetBreakpointPositionsRequest {
 }
 
 impl SourceActor {
-    pub fn new(
-        name: String,
-        url: ServoUrl,
-        content: Option<String>,
-        content_type: Option<String>,
-        spidermonkey_id: u32,
-        introduction_type: String,
-        script_sender: GenericSender<DevtoolScriptControlMsg>,
-    ) -> SourceActor {
-        SourceActor {
-            name,
-            url,
-            content: AtomicRefCell::new(content),
-            content_type,
-            is_black_boxed: false,
-            spidermonkey_id,
-            introduction_type,
-            script_sender,
-        }
-    }
-
     #[expect(clippy::too_many_arguments)]
-    pub fn new_registered(
+    pub fn register(
         registry: &ActorRegistry,
         pipeline_id: PipelineId,
         url: ServoUrl,
@@ -175,21 +154,20 @@ impl SourceActor {
         introduction_type: String,
         script_sender: GenericSender<DevtoolScriptControlMsg>,
     ) -> String {
-        let source_actor_name = registry.new_name::<Self>();
-
-        let source_actor = SourceActor::new(
-            source_actor_name.clone(),
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
             url,
-            content,
+            content: AtomicRefCell::new(content),
             content_type,
+            is_black_boxed: false,
             spidermonkey_id,
             introduction_type,
             script_sender,
-        );
-        registry.register(source_actor);
-        registry.register_source_actor(pipeline_id, &source_actor_name);
-
-        source_actor_name
+        };
+        registry.register::<Self>(actor);
+        registry.register_source_actor(pipeline_id, &name);
+        name
     }
 
     pub fn source_form(&self) -> SourceForm {

components/devtools/actors/stylesheets.rs

@@ -10,11 +10,41 @@ use crate::StreamId;
 use crate::actor::{Actor, ActorError, ActorRegistry};
 use crate::protocol::ClientRequest;
 
+/// <https://searchfox.org/mozilla-central/source/devtools/server/actors/resources/stylesheets.js>
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct StyleSheetData {
+    /// Unique identifier for this stylesheet.
+    resource_id: String,
+    /// The URL of the stylesheet. Optional for inline stylesheets.
+    href: Option<String>,
+    /// The URL of the document that owns this stylesheet.
+    node_href: String,
+    /// Whether the stylesheet is disabled.
+    disabled: bool,
+    /// The title of the stylesheet.
+    title: String,
+    /// Whether this is a browser stylesheet.
+    system: bool,
+    /// Whether this stylesheet was created by DevTools.
+    is_new: bool,
+    /// Optional source map URL.
+    source_map_url: Option<String>,
+    /// The index of this stylesheet in the document's stylesheet list.
+    style_sheet_index: i32,
+    // TODO: the following fields will be implemented later once we fetch the stylesheets
+    // constructed: bool,
+    // file_name: Option<String>,
+    // at_rules: Vec<Rule>,
+    // rule_count: u32,
+    // source_map_base_url: String,
+}
+
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
 struct GetStyleSheetsReply {
     from: String,
-    style_sheets: Vec<u32>, // TODO: real JSON structure.
+    style_sheets: Vec<StyleSheetData>,
 }
 
 #[derive(MallocSizeOf)]
@@ -38,6 +68,7 @@ impl Actor for StyleSheetsActor {
             "getStyleSheets" => {
                 let msg = GetStyleSheetsReply {
                     from: self.name(),
+                    // TODO: Fetch actual stylesheets from the script thread.
                     style_sheets: vec![],
                 };
                 request.reply_final(&msg)?
@@ -50,7 +81,10 @@ impl Actor for StyleSheetsActor {
 }
 
 impl StyleSheetsActor {
-    pub fn new(name: String) -> StyleSheetsActor {
-        StyleSheetsActor { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = StyleSheetsActor { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 }

components/devtools/actors/symbol_iterator.rs

@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use malloc_size_of_derive::MallocSizeOf;
+
+use crate::actor::{Actor, ActorRegistry};
+
+#[derive(MallocSizeOf)]
+pub(crate) struct SymbolIteratorActor {
+    name: String,
+}
+
+impl SymbolIteratorActor {
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
+    }
+}
+
+impl Actor for SymbolIteratorActor {
+    fn name(&self) -> String {
+        self.name.clone()
+    }
+}

components/devtools/actors/tab.rs

@@ -167,19 +167,21 @@ impl Actor for TabDescriptorActor {
 }
 
 impl TabDescriptorActor {
-    pub(crate) fn new(
+    pub(crate) fn register(
         registry: &ActorRegistry,
         browsing_context_name: String,
         is_top_level_global: bool,
-    ) -> TabDescriptorActor {
+    ) -> String {
         let name = registry.new_name::<Self>();
         let root_actor = registry.find::<RootActor>("root");
         root_actor.tabs.borrow_mut().push(name.clone());
-        TabDescriptorActor {
-            name,
+        let actor = TabDescriptorActor {
+            name: name.clone(),
             browsing_context_name,
             is_top_level_global,
-        }
+        };
+        registry.register::<Self>(actor);
+        name
     }
 
     pub(crate) fn is_top_level_global(&self) -> bool {

components/devtools/actors/thread.rs

@@ -116,18 +116,21 @@ pub(crate) struct ThreadActor {
 }
 
 impl ThreadActor {
-    pub fn new(
-        name: String,
+    pub fn register(
+        registry: &ActorRegistry,
         script_sender: GenericSender<DevtoolScriptControlMsg>,
         browsing_context_name: Option<String>,
-    ) -> ThreadActor {
-        ThreadActor {
-            name,
+    ) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = ThreadActor {
+            name: name.clone(),
             source_manager: SourceManager::new(),
             script_sender,
             frames: Default::default(),
             browsing_context_name,
-        }
+        };
+        registry.register::<Self>(actor);
+        name
     }
 }
 
@@ -146,14 +149,11 @@ impl Actor for ThreadActor {
     ) -> Result<(), ActorError> {
         match msg_type {
             "attach" => {
-                let pause = registry.new_name::<PauseActor>();
-                registry.register(PauseActor {
-                    name: pause.clone(),
-                });
+                let pause_name = PauseActor::register(registry);
                 let msg = ThreadAttached {
                     from: self.name(),
                     type_: "paused".to_owned(),
-                    actor: pause,
+                    actor: pause_name,
                     frame: 0,
                     error: 0,
                     recording_endpoint: 0,
@@ -243,7 +243,7 @@ impl Actor for ThreadActor {
                     from: self.name(),
                     frames: result
                         .iter()
-                        .map(|frame| registry.encode::<FrameActor, _>(frame))
+                        .map(|frame_name| registry.encode::<FrameActor, _>(frame_name))
                         .collect(),
                 };
                 request.reply_final(&msg)?

components/devtools/actors/watcher.rs

@@ -23,8 +23,9 @@ use servo_url::ServoUrl;
 use self::network_parent::NetworkParentActor;
 use super::breakpoint::BreakpointListActor;
 use super::thread::ThreadActor;
-use super::worker::WorkerActorMsg;
+use super::worker::WorkerTargetActorMsg;
 use crate::actor::{Actor, ActorEncode, ActorError, ActorRegistry};
+use crate::actors::blackboxing::BlackboxingActor;
 use crate::actors::browsing_context::{BrowsingContextActor, BrowsingContextActorMsg};
 use crate::actors::console::ConsoleActor;
 use crate::actors::root::RootActor;
@@ -34,7 +35,7 @@ use crate::actors::watcher::target_configuration::{
 use crate::actors::watcher::thread_configuration::ThreadConfigurationActor;
 use crate::protocol::{ClientRequest, DevtoolsConnection, JsonPacketStream};
 use crate::resource::{ResourceArrayType, ResourceAvailable};
-use crate::{ActorMsg, EmptyReplyMsg, IdMap, StreamId, WorkerActor};
+use crate::{ActorMsg, EmptyReplyMsg, IdMap, StreamId, WorkerTargetActor};
 
 pub mod network_parent;
 pub mod target_configuration;
@@ -83,7 +84,7 @@ impl SessionContext {
                 ("network-event", true),
                 ("network-event-stacktrace", false),
                 ("reflow", true),
-                ("stylesheet", false),
+                ("stylesheet", true),
                 ("source", true),
                 ("thread-state", false),
                 ("server-sent-event", false),
@@ -110,7 +111,7 @@ pub enum SessionContextType {
 #[serde(untagged)]
 enum TargetActorMsg {
     BrowsingContext(BrowsingContextActorMsg),
-    Worker(WorkerActorMsg),
+    Worker(WorkerTargetActorMsg),
 }
 
 #[derive(Serialize)]
@@ -146,6 +147,13 @@ struct GetThreadConfigurationActorReply {
     configuration: ActorMsg,
 }
 
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct GetBlackboxingActorReply {
+    from: String,
+    blackboxing: ActorMsg,
+}
+
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
 struct GetBreakpointListActorReply {
@@ -184,9 +192,10 @@ pub(crate) struct WatcherActor {
     name: String,
     pub browsing_context_name: String,
     network_parent_name: String,
-    target_configuration: String,
-    thread_configuration: String,
-    breakpoint_list: String,
+    target_configuration_name: String,
+    thread_configuration_name: String,
+    breakpoint_list_name: String,
+    blackboxing_name: String,
     session_context: SessionContext,
 }
 
@@ -266,7 +275,7 @@ impl Actor for WatcherActor {
                             from: self.name(),
                             type_: "target-available-form".into(),
                             target: TargetActorMsg::Worker(
-                                registry.encode::<WorkerActor, _>(worker_name),
+                                registry.encode::<WorkerTargetActor, _>(worker_name),
                             ),
                         };
                         let _ = request.write_json_packet(&worker_msg);
@@ -277,7 +286,7 @@ impl Actor for WatcherActor {
                             from: self.name(),
                             type_: "target-available-form".into(),
                             target: TargetActorMsg::Worker(
-                                registry.encode::<WorkerActor, _>(worker_name),
+                                registry.encode::<WorkerTargetActor, _>(worker_name),
                             ),
                         };
                         let _ = request.write_json_packet(&worker_msg);
@@ -332,7 +341,7 @@ impl Actor for WatcherActor {
                         },
                         "source" => {
                             let thread_actor =
-                                registry.find::<ThreadActor>(&browsing_context_actor.thread);
+                                registry.find::<ThreadActor>(&browsing_context_actor.thread_name);
                             browsing_context_actor.resources_array(
                                 thread_actor.source_manager.source_forms(registry),
                                 resource.into(),
@@ -341,11 +350,12 @@ impl Actor for WatcherActor {
                             );
 
                             for worker_name in &*root_actor.workers.borrow() {
-                                let worker_actor = registry.find::<WorkerActor>(worker_name);
-                                let thread = registry.find::<ThreadActor>(&worker_actor.thread);
+                                let worker_actor = registry.find::<WorkerTargetActor>(worker_name);
+                                let thread_actor =
+                                    registry.find::<ThreadActor>(&worker_actor.thread_name);
 
                                 worker_actor.resources_array(
-                                    thread.source_manager.source_forms(registry),
+                                    thread_actor.source_manager.source_forms(registry),
                                     resource.into(),
                                     ResourceArrayType::Available,
                                     &mut request,
@@ -364,7 +374,7 @@ impl Actor for WatcherActor {
                             );
 
                             for worker_name in &*root_actor.workers.borrow() {
-                                let worker_actor = registry.find::<WorkerActor>(worker_name);
+                                let worker_actor = registry.find::<WorkerTargetActor>(worker_name);
                                 let console_actor =
                                     registry.find::<ConsoleActor>(&worker_actor.console_name);
 
@@ -376,6 +386,17 @@ impl Actor for WatcherActor {
                                 );
                             }
                         },
+                        "stylesheet" => {
+                            // TODO: Fetch actual stylesheets from the script thread.
+                            // For now, send an empty array.
+                            let empty: Vec<serde_json::Value> = vec![];
+                            browsing_context_actor.resources_array(
+                                empty,
+                                resource.into(),
+                                ResourceArrayType::Available,
+                                &mut request,
+                            );
+                        },
                         "network-event" => {},
                         _ => warn!("resource {} not handled yet", resource),
                     }
@@ -405,7 +426,7 @@ impl Actor for WatcherActor {
                 let msg = GetTargetConfigurationActorReply {
                     from: self.name(),
                     configuration: registry
-                        .encode::<TargetConfigurationActor, _>(&self.target_configuration),
+                        .encode::<TargetConfigurationActor, _>(&self.target_configuration_name),
                 };
                 request.reply_final(&msg)?
             },
@@ -413,7 +434,7 @@ impl Actor for WatcherActor {
                 let msg = GetThreadConfigurationActorReply {
                     from: self.name(),
                     configuration: registry
-                        .encode::<ThreadConfigurationActor, _>(&self.thread_configuration),
+                        .encode::<ThreadConfigurationActor, _>(&self.thread_configuration_name),
                 };
                 request.reply_final(&msg)?
             },
@@ -421,7 +442,14 @@ impl Actor for WatcherActor {
                 let msg = GetBreakpointListActorReply {
                     from: self.name(),
                     breakpoint_list: registry
-                        .encode::<BreakpointListActor, _>(&self.breakpoint_list),
+                        .encode::<BreakpointListActor, _>(&self.breakpoint_list_name),
+                };
+                request.reply_final(&msg)?
+            },
+            "getBlackboxingActor" => {
+                let msg = GetBlackboxingActorReply {
+                    from: self.name(),
+                    blackboxing: registry.encode::<BlackboxingActor, _>(&self.blackboxing_name),
                 };
                 request.reply_final(&msg)?
             },
@@ -438,38 +466,33 @@ impl ResourceAvailable for WatcherActor {
 }
 
 impl WatcherActor {
-    pub fn new(
+    pub fn register(
         registry: &ActorRegistry,
         browsing_context_name: String,
         session_context: SessionContext,
-    ) -> Self {
-        let network_parent_actor =
-            NetworkParentActor::new(registry.new_name::<NetworkParentActor>());
-        let target_configuration =
-            TargetConfigurationActor::new(registry.new_name::<TargetConfigurationActor>());
-        let thread_configuration =
-            ThreadConfigurationActor::new(registry.new_name::<ThreadConfigurationActor>());
-        let breakpoint_list = BreakpointListActor::new(
-            registry.new_name::<BreakpointListActor>(),
-            browsing_context_name.clone(),
-        );
+    ) -> String {
+        let network_parent_name = NetworkParentActor::register(registry);
+        let target_configuration_name = TargetConfigurationActor::register(registry);
+        let thread_configuration_name = ThreadConfigurationActor::register(registry);
+        let breakpoint_list_name =
+            BreakpointListActor::register(registry, browsing_context_name.clone());
+        let blackboxing_name = BlackboxingActor::register(registry);
 
-        let watcher_actor = Self {
-            name: registry.new_name::<WatcherActor>(),
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
             browsing_context_name,
-            network_parent_name: network_parent_actor.name(),
-            target_configuration: target_configuration.name(),
-            thread_configuration: thread_configuration.name(),
-            breakpoint_list: breakpoint_list.name(),
+            network_parent_name,
+            target_configuration_name,
+            thread_configuration_name,
+            breakpoint_list_name,
+            blackboxing_name,
             session_context,
         };
 
-        registry.register(network_parent_actor);
-        registry.register(target_configuration);
-        registry.register(thread_configuration);
-        registry.register(breakpoint_list);
+        registry.register::<Self>(actor);
 
-        watcher_actor
+        name
     }
 
     pub fn emit_will_navigate<'a>(

components/devtools/actors/watcher/network_parent.rs

@@ -46,8 +46,11 @@ impl Actor for NetworkParentActor {
 }
 
 impl NetworkParentActor {
-    pub fn new(name: String) -> Self {
-        Self { name }
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self { name: name.clone() };
+        registry.register::<Self>(actor);
+        name
     }
 }
 

components/devtools/actors/watcher/target_configuration.rs

@@ -105,9 +105,10 @@ impl Actor for TargetConfigurationActor {
 }
 
 impl TargetConfigurationActor {
-    pub fn new(name: String) -> Self {
-        Self {
-            name,
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
             configuration: HashMap::new(),
             supported_options: HashMap::from([
                 ("cacheDisabled", false),
@@ -128,7 +129,9 @@ impl TargetConfigurationActor {
                 ("tracerOptions", false),
                 ("useSimpleHighlightersForReducedMotion", false),
             ]),
-        }
+        };
+        registry.register::<Self>(actor);
+        name
     }
 }
 

components/devtools/actors/watcher/thread_configuration.rs

@@ -49,11 +49,14 @@ impl Actor for ThreadConfigurationActor {
 }
 
 impl ThreadConfigurationActor {
-    pub fn new(name: String) -> Self {
-        Self {
-            name,
+    pub fn register(registry: &ActorRegistry) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
             _configuration: HashMap::new(),
-        }
+        };
+        registry.register::<Self>(actor);
+        name
     }
 }
 

components/devtools/actors/worker.rs

@@ -27,24 +27,50 @@ pub enum WorkerType {
 }
 
 #[derive(MallocSizeOf)]
-pub(crate) struct WorkerActor {
+pub(crate) struct WorkerTargetActor {
     pub name: String,
     pub console_name: String,
-    pub thread: String,
+    pub thread_name: String,
     pub worker_id: WorkerId,
     pub url: ServoUrl,
     pub type_: WorkerType,
-    pub script_chan: GenericSender<DevtoolScriptControlMsg>,
+    pub script_sender: GenericSender<DevtoolScriptControlMsg>,
     pub streams: AtomicRefCell<FxHashSet<StreamId>>,
 }
 
-impl ResourceAvailable for WorkerActor {
+impl ResourceAvailable for WorkerTargetActor {
     fn actor_name(&self) -> String {
         self.name.clone()
     }
 }
 
-impl Actor for WorkerActor {
+impl WorkerTargetActor {
+    pub fn register(
+        registry: &ActorRegistry,
+        console_name: String,
+        thread_name: String,
+        worker_id: WorkerId,
+        url: ServoUrl,
+        worker_type: WorkerType,
+        script_sender: GenericSender<DevtoolScriptControlMsg>,
+    ) -> String {
+        let name = registry.new_name::<Self>();
+        let actor = Self {
+            name: name.clone(),
+            console_name,
+            thread_name,
+            worker_id,
+            url,
+            type_: worker_type,
+            script_sender,
+            streams: Default::default(),
+        };
+        registry.register::<Self>(actor);
+        name
+    }
+}
+
+impl Actor for WorkerTargetActor {
     fn name(&self) -> String {
         self.name.clone()
     }
@@ -67,7 +93,7 @@ impl Actor for WorkerActor {
                 request.write_json_packet(&msg)?;
                 self.streams.borrow_mut().insert(stream_id);
                 // FIXME: fix messages to not require forging a pipeline for worker messages
-                self.script_chan
+                self.script_sender
                     .send(WantsLiveNotifications(TEST_PIPELINE_ID, true))
                     .unwrap();
             },
@@ -76,7 +102,7 @@ impl Actor for WorkerActor {
                 let msg = ConnectReply {
                     from: self.name(),
                     type_: "connected".to_owned(),
-                    thread_actor: self.thread.clone(),
+                    thread_actor: self.thread_name.clone(),
                     console_actor: self.console_name.clone(),
                 };
                 // FIXME: we don’t send an actual reply (message without type), which seems to be a bug?
@@ -109,7 +135,7 @@ impl Actor for WorkerActor {
     fn cleanup(&self, stream_id: StreamId) {
         self.streams.borrow_mut().remove(&stream_id);
         if self.streams.borrow().is_empty() {
-            self.script_chan
+            self.script_sender
                 .send(WantsLiveNotifications(TEST_PIPELINE_ID, false))
                 .unwrap();
         }
@@ -156,7 +182,7 @@ struct WorkerTraits {
 
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
-pub(crate) struct WorkerActorMsg {
+pub(crate) struct WorkerTargetActorMsg {
     actor: String,
     console_actor: String,
     thread_actor: String,
@@ -169,12 +195,12 @@ pub(crate) struct WorkerActorMsg {
     target_type: String,
 }
 
-impl ActorEncode<WorkerActorMsg> for WorkerActor {
-    fn encode(&self, _: &ActorRegistry) -> WorkerActorMsg {
-        WorkerActorMsg {
+impl ActorEncode<WorkerTargetActorMsg> for WorkerTargetActor {
+    fn encode(&self, _: &ActorRegistry) -> WorkerTargetActorMsg {
+        WorkerTargetActorMsg {
             actor: self.name(),
             console_actor: self.console_name.clone(),
-            thread_actor: self.thread.clone(),
+            thread_actor: self.thread_name.clone(),
             id: self.worker_id.0.to_string(),
             url: self.url.to_string(),
             traits: WorkerTraits {

components/devtools/build.rs

@@ -5,16 +5,29 @@
 use std::path::Path;
 use std::{env, fs};
 
-use chrono::Local;
+use chrono::{TimeZone, Utc};
 
 fn main() {
+    println!("cargo:rerun-if-env-changed=SOURCE_DATE_EPOCH");
+    // Parsing as suggested on <https://reproducible-builds.org/docs/source-date-epoch/>
+    let now = match env::var("SOURCE_DATE_EPOCH") {
+        Ok(val) => Utc
+            .timestamp_opt(
+                val.parse::<i64>()
+                    .expect("SOURCE_DATE_EPOCH should be a valid integer"),
+                0,
+            )
+            .unwrap(),
+        Err(_) => Utc::now(),
+    };
+
+    let build_id = now.format("%Y%m%d%H%M%S").to_string();
+
     let path = Path::new(&env::var_os("OUT_DIR").unwrap()).join("build_id.rs");
-    fs::write(
-        path,
-        format!(
-            "const BUILD_ID: &str = \"{}\";",
-            Local::now().format("%Y%m%d%H%M%S")
-        ),
-    )
-    .unwrap();
+    // The build ID is used in Firefox devtools, `getDateFromBuildID` function:
+    // <https://searchfox.org/firefox-main/rev/be31b3948198286e39a9855e414823cb17b6e94c/devtools/client/shared/remote-debugging/version-checker.js#21-24>
+    // The expected format is: yyyyMMddHHmmss.
+    // The date is than later used to check devtools compatibility:
+    // <https://searchfox.org/firefox-main/rev/be31b3948198286e39a9855e414823cb17b6e94c/devtools/client/shared/remote-debugging/version-checker.js#133-139>
+    fs::write(path, format!("const BUILD_ID: &str = \"{build_id}\";")).unwrap();
 }

components/devtools/lib.rs

@@ -22,9 +22,9 @@ use std::thread;
 use crossbeam_channel::{Receiver, Sender, unbounded};
 use devtools_traits::{
     ChromeToDevtoolsControlMsg, ConsoleLogLevel, ConsoleMessage, ConsoleMessageFields,
-    DevtoolScriptControlMsg, DevtoolsControlMsg, DevtoolsPageInfo, DomMutation, EnvironmentInfo,
-    FrameInfo, FrameOffset, NavigationState, NetworkEvent, PauseReason, ScriptToDevtoolsControlMsg,
-    SourceInfo, WorkerId, get_time_stamp,
+    DebuggerValue, DevtoolScriptControlMsg, DevtoolsControlMsg, DevtoolsPageInfo, DomMutation,
+    EnvironmentInfo, FrameInfo, FrameOffset, NavigationState, NetworkEvent, PauseReason,
+    ScriptToDevtoolsControlMsg, SourceInfo, WorkerId, get_time_stamp,
 };
 use embedder_traits::{AllowOrDeny, EmbedderMsg, EmbedderProxy};
 use log::{trace, warn};
@@ -35,6 +35,7 @@ use rand::{RngCore, rng};
 use resource::{ResourceArrayType, ResourceAvailable};
 use rustc_hash::FxHashMap;
 use serde::Serialize;
+use serde_json::{Map, Number, Value};
 use servo_base::generic_channel::{self, GenericSender};
 use servo_base::id::{BrowsingContextId, PipelineId, WebViewId};
 use servo_config::pref;
@@ -48,12 +49,13 @@ use crate::actors::framerate::FramerateActor;
 use crate::actors::inspector::InspectorActor;
 use crate::actors::inspector::walker::WalkerActor;
 use crate::actors::network_event::NetworkEventActor;
+use crate::actors::object::ObjectActor;
 use crate::actors::pause::PauseActor;
 use crate::actors::root::RootActor;
 use crate::actors::source::SourceActor;
 use crate::actors::thread::{ThreadActor, ThreadInterruptedReply};
 use crate::actors::watcher::WatcherActor;
-use crate::actors::worker::{WorkerActor, WorkerType};
+use crate::actors::worker::{WorkerTargetActor, WorkerType};
 use crate::id::IdMap;
 use crate::network_handler::handle_network_event;
 use crate::protocol::{DevtoolsConnection, JsonPacketStream};
@@ -61,6 +63,7 @@ use crate::protocol::{DevtoolsConnection, JsonPacketStream};
 mod actor;
 /// <https://searchfox.org/mozilla-central/source/devtools/server/actors>
 mod actors {
+    pub mod blackboxing;
     pub mod breakpoint;
     pub mod browsing_context;
     pub mod console;
@@ -82,6 +85,7 @@ mod actors {
     pub mod root;
     pub mod source;
     pub mod stylesheets;
+    pub mod symbol_iterator;
     pub mod tab;
     pub mod thread;
     pub mod timeline;
@@ -345,7 +349,7 @@ impl DevtoolsInstance {
                             column_number: css_error.column,
                             time_stamp: get_time_stamp(),
                         },
-                        arguments: vec![css_error.msg.into()],
+                        arguments: vec![DebuggerValue::StringValue(css_error.msg)],
                         stacktrace: None,
                     };
                     let console_message =
@@ -475,42 +479,33 @@ impl DevtoolsInstance {
         let console_name = self.registry.new_name::<ConsoleActor>();
 
         let parent_actor = if let Some(id) = worker_id {
-            let thread = ThreadActor::new(
-                self.registry.new_name::<ThreadActor>(),
-                script_sender.clone(),
-                None,
-            );
-            let thread_name = thread.name();
-            self.registry.register(thread);
+            let thread_name = ThreadActor::register(&self.registry, script_sender.clone(), None);
 
             let worker_type = if page_info.is_service_worker {
                 WorkerType::Service
             } else {
                 WorkerType::Dedicated
             };
-            let worker_name = self.registry.new_name::<WorkerActor>();
-            let worker = WorkerActor {
-                name: worker_name.clone(),
-                console_name: console_name.clone(),
-                thread: thread_name,
-                worker_id: id,
-                url: page_info.url,
-                type_: worker_type,
-                script_chan: script_sender,
-                streams: Default::default(),
-            };
+            let worker_name = WorkerTargetActor::register(
+                &self.registry,
+                console_name.clone(),
+                thread_name,
+                id,
+                page_info.url,
+                worker_type,
+                script_sender,
+            );
             let root_actor = self.registry.find::<RootActor>("root");
             if page_info.is_service_worker {
                 root_actor
                     .service_workers
                     .borrow_mut()
-                    .push(worker.name.clone());
+                    .push(worker_name.clone());
             } else {
-                root_actor.workers.borrow_mut().push(worker.name.clone());
+                root_actor.workers.borrow_mut().push(worker_name.clone());
             }
 
             self.actor_workers.insert(id, worker_name.clone());
-            self.registry.register(worker);
 
             Root::DedicatedWorker(worker_name)
         } else {
@@ -519,7 +514,8 @@ impl DevtoolsInstance {
                 .browsing_contexts
                 .entry(browsing_context_id)
                 .or_insert_with(|| {
-                    let browsing_context_actor = BrowsingContextActor::new(
+                    BrowsingContextActor::register(
+                        &self.registry,
                         console_name.clone(),
                         devtools_browser_id,
                         devtools_browsing_context_id,
@@ -527,11 +523,7 @@ impl DevtoolsInstance {
                         pipeline_id,
                         devtools_outer_window_id,
                         script_sender.clone(),
-                        &self.registry,
-                    );
-                    let browsing_context_name = browsing_context_actor.name();
-                    self.registry.register(browsing_context_actor);
-                    browsing_context_name
+                    )
                 });
             let browsing_context_actor = self
                 .registry
@@ -540,9 +532,7 @@ impl DevtoolsInstance {
             Root::BrowsingContext(browsing_context_name.clone())
         };
 
-        let console_actor = ConsoleActor::new(console_name, parent_actor);
-
-        self.registry.register(console_actor);
+        ConsoleActor::register(&self.registry, console_name, parent_actor);
     }
 
     fn handle_title_changed(&self, pipeline_id: PipelineId, title: String) {
@@ -600,8 +590,10 @@ impl DevtoolsInstance {
             .find::<BrowsingContextActor>(browsing_context_name);
         let inspector_actor = self
             .registry
-            .find::<InspectorActor>(&browsing_context_actor.inspector);
-        let walker_actor = self.registry.find::<WalkerActor>(&inspector_actor.walker);
+            .find::<InspectorActor>(&browsing_context_actor.inspector_name);
+        let walker_actor = self
+            .registry
+            .find::<WalkerActor>(&inspector_actor.walker_name);
 
         for connection in self.connections.lock().unwrap().values_mut() {
             walker_actor.handle_dom_mutation(dom_mutation.clone(), connection)?;
@@ -632,7 +624,7 @@ impl DevtoolsInstance {
             let worker_name = self.actor_workers.get(&worker_id)?;
             Some(
                 self.registry
-                    .find::<WorkerActor>(worker_name)
+                    .find::<WorkerTargetActor>(worker_name)
                     .console_name
                     .clone(),
             )
@@ -688,13 +680,11 @@ impl DevtoolsInstance {
         let resource_id = self.next_resource_id;
         self.next_resource_id += 1;
 
-        let network_event_name = self.registry.new_name::<NetworkEventActor>();
-        let network_event_actor =
-            NetworkEventActor::new(network_event_name.clone(), resource_id, watcher_name);
+        let network_event_name =
+            NetworkEventActor::register(&self.registry, resource_id, watcher_name);
 
         self.actor_requests
             .insert(request_id, network_event_name.clone());
-        self.registry.register(network_event_actor);
 
         network_event_name
     }
@@ -708,7 +698,7 @@ impl DevtoolsInstance {
         let source_content = source_info
             .content
             .or_else(|| self.registry.inline_source_content(pipeline_id));
-        let source_actor = SourceActor::new_registered(
+        let source_actor = SourceActor::register(
             &self.registry,
             pipeline_id,
             source_info.url,
@@ -730,14 +720,14 @@ impl DevtoolsInstance {
 
             let thread_actor_name = self
                 .registry
-                .find::<WorkerActor>(worker_name)
-                .thread
+                .find::<WorkerTargetActor>(worker_name)
+                .thread_name
                 .clone();
             let thread_actor = self.registry.find::<ThreadActor>(&thread_actor_name);
 
             thread_actor.source_manager.add_source(&source_actor);
 
-            let worker_actor = self.registry.find::<WorkerActor>(worker_name);
+            let worker_actor = self.registry.find::<WorkerTargetActor>(worker_name);
 
             for stream in self.connections.lock().unwrap().values_mut() {
                 worker_actor.resource_array(
@@ -760,7 +750,7 @@ impl DevtoolsInstance {
                 let browsing_context_actor = self
                     .registry
                     .find::<BrowsingContextActor>(browsing_context_name);
-                browsing_context_actor.thread.clone()
+                browsing_context_actor.thread_name.clone()
             };
 
             let thread_actor = self.registry.find::<ThreadActor>(&thread_actor_name);
@@ -783,8 +773,8 @@ impl DevtoolsInstance {
     }
 
     fn handle_update_source_content(&mut self, pipeline_id: PipelineId, source_content: String) {
-        for actor_name in self.registry.source_actor_names_for_pipeline(pipeline_id) {
-            let source_actor = self.registry.find::<SourceActor>(&actor_name);
+        for source_name in self.registry.source_actor_names_for_pipeline(pipeline_id) {
+            let source_actor = self.registry.find::<SourceActor>(&source_name);
             let mut content = source_actor.content.borrow_mut();
             if content.is_none() {
                 *content = Some(source_content.clone());
@@ -814,23 +804,20 @@ impl DevtoolsInstance {
         let browsing_context_actor = self
             .registry
             .find::<BrowsingContextActor>(browsing_context_name);
-        let thread = self
+        let thread_actor = self
             .registry
-            .find::<ThreadActor>(&browsing_context_actor.thread);
+            .find::<ThreadActor>(&browsing_context_actor.thread_name);
 
-        let pause = self.registry.new_name::<PauseActor>();
-        self.registry.register(PauseActor {
-            name: pause.clone(),
-        });
+        let pause_name = PauseActor::register(&self.registry);
 
-        let frame = self.registry.find::<FrameActor>(&frame_offset.actor);
-        frame.set_offset(frame_offset.column, frame_offset.line);
+        let frame_actor = self.registry.find::<FrameActor>(&frame_offset.actor);
+        frame_actor.set_offset(frame_offset.column, frame_offset.line);
 
         let msg = ThreadInterruptedReply {
-            from: thread.name(),
+            from: thread_actor.name(),
             type_: "paused".to_owned(),
-            actor: pause,
-            frame: frame.encode(&self.registry),
+            actor: pause_name,
+            frame: frame_actor.encode(&self.registry),
             why: pause_reason,
         };
 
@@ -856,34 +843,34 @@ impl DevtoolsInstance {
         let browsing_context_actor = self
             .registry
             .find::<BrowsingContextActor>(browsing_context_name);
-        let thread = self
+        let thread_actor = self
             .registry
-            .find::<ThreadActor>(&browsing_context_actor.thread);
+            .find::<ThreadActor>(&browsing_context_actor.thread_name);
 
-        let source = match thread
+        let source_name = match thread_actor
             .source_manager
             .find_source(&self.registry, &frame.url)
         {
-            Some(source) => source.name(),
+            Some(source_actor) => source_actor.name(),
             None => {
                 warn!("No source actor found for URL: {}", frame.url);
                 return;
             },
         };
 
-        let frame = FrameActor::register(&self.registry, source, frame);
+        let frame_name = FrameActor::register(&self.registry, source_name, frame);
 
-        let _ = result_sender.send(frame);
+        let _ = result_sender.send(frame_name);
     }
 
     fn handle_create_environment_actor(
         &mut self,
         result_sender: GenericSender<String>,
-        environment: EnvironmentInfo,
+        environment_info: EnvironmentInfo,
         parent: Option<String>,
     ) {
-        let frame = EnvironmentActor::register(&self.registry, environment, parent);
-        let _ = result_sender.send(frame);
+        let environment_name = EnvironmentActor::register(&self.registry, environment_info, parent);
+        let _ = result_sender.send(environment_name);
     }
 }
 
@@ -964,3 +951,51 @@ fn handle_client(
 
     registry.cleanup(stream_id);
 }
+
+/// <https://searchfox.org/mozilla-central/source/devtools/server/actors/object/utils.js#148>
+pub(crate) fn debugger_value_to_json(registry: &ActorRegistry, value: DebuggerValue) -> Value {
+    let mut v = Map::new();
+    match value {
+        DebuggerValue::VoidValue => {
+            v.insert("type".to_owned(), Value::String("undefined".to_owned()));
+            Value::Object(v)
+        },
+        DebuggerValue::NullValue => {
+            v.insert("type".to_owned(), Value::String("null".to_owned()));
+            Value::Object(v)
+        },
+        DebuggerValue::BooleanValue(boolean) => Value::Bool(boolean),
+        DebuggerValue::NumberValue(val) => {
+            if val.is_nan() {
+                v.insert("type".to_owned(), Value::String("NaN".to_owned()));
+                Value::Object(v)
+            } else if val.is_infinite() {
+                if val < 0. {
+                    v.insert("type".to_owned(), Value::String("-Infinity".to_owned()));
+                } else {
+                    v.insert("type".to_owned(), Value::String("Infinity".to_owned()));
+                }
+                Value::Object(v)
+            } else if val == 0. && val.is_sign_negative() {
+                v.insert("type".to_owned(), Value::String("-0".to_owned()));
+                Value::Object(v)
+            } else {
+                Value::Number(Number::from_f64(val).unwrap())
+            }
+        },
+        DebuggerValue::StringValue(str) => Value::String(str),
+        DebuggerValue::ObjectValue {
+            uuid,
+            class,
+            preview,
+            ..
+        } => {
+            // TODO: We should have a field called `ownPropertyLength` here
+            // That will show "{...}" when an object has more properties
+            let object_name = ObjectActor::register(registry, Some(uuid), class, preview);
+            let object_msg = registry.encode::<ObjectActor, _>(&object_name);
+            let value = serde_json::to_value(object_msg).unwrap_or_default();
+            Value::Object(value.as_object().cloned().unwrap_or_default())
+        },
+    }
+}

components/devtools/protocol.rs

@@ -9,7 +9,6 @@ use std::io::{self, ErrorKind, Read, Write};
 use std::net::{Shutdown, SocketAddr, TcpStream};
 use std::sync::{Arc, Mutex};
 
-use log::debug;
 use malloc_size_of_derive::MallocSizeOf;
 use serde::Serialize;
 use serde_json::{self, Value, json};
@@ -36,53 +35,6 @@ pub trait JsonPacketStream {
     fn read_json_packet(&mut self) -> Result<Option<Value>, String>;
 }
 
-impl JsonPacketStream for TcpStream {
-    fn write_json_packet<T: Serialize>(&mut self, message: &T) -> Result<(), ActorError> {
-        let s = serde_json::to_string(message).map_err(|_| ActorError::Internal)?;
-        debug!("<- {}", s);
-        write!(self, "{}:{}", s.len(), s).map_err(|_| ActorError::Internal)?;
-        Ok(())
-    }
-
-    fn read_json_packet(&mut self) -> Result<Option<Value>, String> {
-        // https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#stream-transport
-        // In short, each JSON packet is [ascii length]:[JSON data of given length]
-        let mut buffer = vec![];
-        loop {
-            let mut buf = [0];
-            let byte = match self.read(&mut buf) {
-                Ok(0) => return Ok(None),                                            // EOF
-                Err(e) if e.kind() == ErrorKind::ConnectionReset => return Ok(None), // EOF
-                Ok(1) => buf[0],
-                Ok(_) => unreachable!(),
-                Err(e) => return Err(e.to_string()),
-            };
-            match byte {
-                b':' => {
-                    let packet_len_str = match String::from_utf8(buffer) {
-                        Ok(packet_len) => packet_len,
-                        Err(_) => return Err("nonvalid UTF8 in packet length".to_owned()),
-                    };
-                    let packet_len = match packet_len_str.parse::<u64>() {
-                        Ok(packet_len) => packet_len,
-                        Err(_) => return Err("packet length missing / not parsable".to_owned()),
-                    };
-                    let mut packet = String::new();
-                    self.take(packet_len)
-                        .read_to_string(&mut packet)
-                        .map_err(|e| e.to_string())?;
-                    debug!("{}", packet);
-                    return match serde_json::from_str(&packet) {
-                        Ok(json) => Ok(Some(json)),
-                        Err(err) => Err(err.to_string()),
-                    };
-                },
-                c => buffer.push(c),
-            }
-        }
-    }
-}
-
 /// Wraps a Remote Debugging Protocol TCP stream, guaranteeing that network
 /// operations are synchronized when cloning across threads.
 #[derive(Clone, MallocSizeOf)]

components/fonts/Cargo.toml

@@ -66,11 +66,11 @@ objc2-core-foundation = { workspace = true }
 objc2-core-graphics = { workspace = true }
 objc2-core-text = { workspace = true }
 
-[target.'cfg(any(target_os = "linux", target_os = "android"))'.dependencies]
+[target.'cfg(any(target_os = "linux", target_os = "android", target_os = "freebsd"))'.dependencies]
 freetype-sys = { workspace = true }
 servo-allocator = { workspace = true }
 
-[target.'cfg(all(target_os = "linux", not(target_env = "ohos")))'.dependencies]
+[target.'cfg(all(any(target_os = "linux", target_os = "freebsd"), not(target_env = "ohos")))'.dependencies]
 fontconfig_sys = { package = "yeslogic-fontconfig-sys", version = "6" }
 
 [target.'cfg(target_os = "android")'.dependencies]

components/fonts/font.rs

@@ -32,7 +32,7 @@ use style::properties::style_structs::Font as FontStyleStruct;
 use style::values::computed::font::{
     FamilyName, FontFamilyNameSyntax, GenericFontFamily, SingleFontFamily,
 };
-use style::values::computed::{FontStretch, FontStyle, FontSynthesis, FontWeight, XLang};
+use style::values::computed::{FontStretch, FontStyle, FontSynthesis, FontWeight};
 use unicode_script::Script;
 use webrender_api::{FontInstanceFlags, FontInstanceKey, FontVariation};
 
@@ -389,7 +389,7 @@ pub struct ShapingOptions {
     /// determine the amount of spacing to apply.
     pub letter_spacing: Option<Au>,
     /// Spacing to add between each word. Corresponds to the CSS 2.1 `word-spacing` property.
-    pub word_spacing: Au,
+    pub word_spacing: Option<Au>,
     /// The Unicode script property of the characters in this run.
     pub script: Script,
     /// The preferred language, obtained from the `lang` attribute.
@@ -470,7 +470,7 @@ impl Font {
 
     /// Fast path for ASCII text that only needs simple horizontal LTR kerning.
     fn shape_text_fast(&self, text: &str, options: &ShapingOptions) -> GlyphStore {
-        let mut glyph_store = GlyphStore::new(text, text.len(), options);
+        let mut glyph_store = GlyphStore::new(text.len(), options);
         let mut prev_glyph_id = None;
         for (string_byte_offset, byte) in text.bytes().enumerate() {
             let character = byte as char;
@@ -478,26 +478,22 @@ impl Font {
                 continue;
             };
 
-            let mut advance = advance_for_shaped_glyph(
-                Au::from_f64_px(self.glyph_h_advance(glyph_id)),
-                character,
-                options,
-            );
+            let mut advance = Au::from_f64_px(self.glyph_h_advance(glyph_id));
             let offset = prev_glyph_id.map(|prev| {
                 let h_kerning = Au::from_f64_px(self.glyph_h_kerning(prev, glyph_id));
                 advance += h_kerning;
                 Point2D::new(h_kerning, Au::zero())
             });
 
-            glyph_store.add_glyph(
-                character,
-                &ShapedGlyph {
-                    glyph_id,
-                    string_byte_offset,
-                    advance,
-                    offset,
-                },
-            );
+            let mut glyph = ShapedGlyph {
+                glyph_id,
+                string_byte_offset,
+                advance,
+                offset,
+            };
+            glyph.adjust_for_character(character, options, self);
+
+            glyph_store.add_glyph(character, &glyph);
             prev_glyph_id = Some(glyph_id);
         }
         glyph_store
@@ -600,7 +596,7 @@ impl Deref for FontRef {
 pub struct FallbackKey {
     script: Script,
     unicode_block: Option<UnicodeBlock>,
-    lang: XLang,
+    language: Language,
 }
 
 impl FallbackKey {
@@ -608,7 +604,7 @@ impl FallbackKey {
         Self {
             script: Script::from(options.character),
             unicode_block: options.character.block(),
-            lang: options.lang.clone(),
+            language: options.language,
         }
     }
 }
@@ -656,7 +652,7 @@ impl FontGroup {
         font_context: &FontContext,
         codepoint: char,
         next_codepoint: Option<char>,
-        lang: XLang,
+        language: Language,
     ) -> Option<FontRef> {
         // Tab characters are converted into spaces when rendering.
         // TODO: We should not render a tab character. Instead they should be converted into tab stops
@@ -666,7 +662,7 @@ impl FontGroup {
             _ => codepoint,
         };
 
-        let options = FallbackFontSelectionOptions::new(codepoint, next_codepoint, lang);
+        let options = FallbackFontSelectionOptions::new(codepoint, next_codepoint, language);
 
         let should_look_for_small_caps = self.descriptor.variant == font_variant_caps::T::SmallCaps &&
             options.character.is_ascii_lowercase();
@@ -962,7 +958,7 @@ pub struct FontBaseline {
 /// let mapped_weight = apply_font_config_to_style_mapping(&mapping, weight as f64);
 /// ```
 #[cfg(all(
-    any(target_os = "linux", target_os = "macos"),
+    any(target_os = "linux", target_os = "macos", target_os = "freebsd"),
     not(target_env = "ohos")
 ))]
 pub(crate) fn map_platform_values_to_style_values(mapping: &[(f64, f64)], value: f64) -> f64 {
@@ -982,25 +978,3 @@ pub(crate) fn map_platform_values_to_style_values(mapping: &[(f64, f64)], value:
 
     mapping[mapping.len() - 1].1
 }
-
-/// Computes the total advance for a glyph, taking `letter-spacing` and `word-spacing` into account.
-pub(super) fn advance_for_shaped_glyph(
-    mut advance: Au,
-    character: char,
-    options: &ShapingOptions,
-) -> Au {
-    if let Some(letter_spacing) = options.letter_spacing_for_character(character) {
-        advance += letter_spacing;
-    };
-
-    // CSS 2.1 § 16.4 states that "word spacing affects each space (U+0020) and non-breaking
-    // space (U+00A0) left in the text after the white space processing rules have been
-    // applied. The effect of the property on other word-separator characters is undefined."
-    // We elect to only space the two required code points.
-    if character == ' ' || character == '\u{a0}' {
-        // https://drafts.csswg.org/css-text-3/#word-spacing-property
-        advance += options.word_spacing;
-    }
-
-    advance
-}

components/fonts/font_context.rs

@@ -16,6 +16,7 @@ use fonts_traits::{
 };
 use log::{debug, trace};
 use malloc_size_of_derive::MallocSizeOf;
+use net_traits::blob_url_store::UrlWithBlobClaim;
 use net_traits::policy_container::PolicyContainer;
 use net_traits::request::{
     CredentialsMode, Destination, InsecureRequestsPolicy, Referrer, RequestBuilder, RequestClient,
@@ -646,7 +647,15 @@ impl FontContextWebFontMethods for Arc<FontContext> {
             };
 
             let rule: &FontFaceRule = lock.read_with(guard);
-            let Some(font_face) = rule.font_face() else {
+
+            // Per https://github.com/w3c/csswg-drafts/issues/1133 an @font-face rule
+            // is valid as far as the CSS parser is concerned even if it doesn’t have
+            // a font-family or src declaration.
+            // However, both are required for the rule to represent an actual font face.
+            if rule.descriptors.font_family.is_none() {
+                continue;
+            }
+            let Some(ref sources) = rule.descriptors.src else {
                 continue;
             };
 
@@ -661,7 +670,7 @@ impl FontContextWebFontMethods for Arc<FontContext> {
             number_loading += 1;
             self.start_loading_one_web_font(
                 Some(webview_id),
-                font_face.sources(),
+                sources,
                 css_font_face_descriptors,
                 WebFontLoadInitiator::Stylesheet(Box::new(initiator)),
                 document_context,
@@ -978,7 +987,7 @@ impl RemoteWebFontDownloader {
 
         let request = RequestBuilder::new(
             state.webview_id,
-            url.clone().into(),
+            UrlWithBlobClaim::from_url_without_having_claimed_blob(url.clone().into()),
             Referrer::ReferrerUrl(document_context.document_url.clone()),
         )
         .destination(Destination::Font)

components/fonts/glyph.rs

@@ -243,10 +243,6 @@ pub struct GlyphStore {
     /// but that may not be the case with `white-space: break-spaces`.
     ends_with_whitespace: bool,
 
-    /// Whether or not this glyph store contains only a single glyph for a single
-    /// preserved newline.
-    is_single_preserved_newline: bool,
-
     /// Whether or not this [`GlyphStore`] has right-to-left text, which has implications
     /// about the order of the glyphs in the store.
     is_rtl: bool,
@@ -256,7 +252,7 @@ impl GlyphStore {
     /// Initializes the glyph store with the given capacity, but doesn't actually add any glyphs.
     ///
     /// Use the `add_*` methods to store glyph data.
-    pub(crate) fn new(text: &str, length: usize, options: &ShapingOptions) -> Self {
+    pub(crate) fn new(length: usize, options: &ShapingOptions) -> Self {
         Self {
             glyphs: Vec::with_capacity(length),
             detailed_glyphs: Default::default(),
@@ -269,7 +265,6 @@ impl GlyphStore {
             ends_with_whitespace: options
                 .flags
                 .contains(ShapingFlags::ENDS_WITH_WHITESPACE_SHAPING_FLAG),
-            is_single_preserved_newline: text.len() == 1 && text.starts_with('\n'),
             is_rtl: options.flags.contains(ShapingFlags::RTL_FLAG),
         }
     }
@@ -303,7 +298,7 @@ impl GlyphStore {
         };
 
         let mut previous_character_offset = None;
-        let mut glyph_store = GlyphStore::new(text, shaped_glyph_data.len(), options);
+        let mut glyph_store = GlyphStore::new(shaped_glyph_data.len(), options);
         for mut shaped_glyph in shaped_glyph_data.iter() {
             // The glyph "cluster" (HarfBuzz terminology) is the byte offset in the string that
             // this glyph corresponds to. More than one glyph can share a cluster.
@@ -389,12 +384,6 @@ impl GlyphStore {
         self.is_whitespace
     }
 
-    /// Whether or not this [`GlyphStore`] is a single preserved newline.
-    #[inline]
-    pub fn is_single_preserved_newline(&self) -> bool {
-        self.is_single_preserved_newline
-    }
-
     /// Whether or not this [`GlyphStore`] ends with whitespace.
     #[inline]
     pub fn ends_with_whitespace(&self) -> bool {
@@ -540,7 +529,7 @@ impl ShapedGlyph {
     /// TODO: This should all likely move to layout. In particular, proper tab stops
     /// are context sensitive and be based on the size of the space character in the
     /// inline formatting context.
-    fn adjust_for_character(
+    pub(crate) fn adjust_for_character(
         &mut self,
         character: char,
         shaping_options: &ShapingOptions,
@@ -561,9 +550,11 @@ impl ShapedGlyph {
         // space (U+00A0) left in the text after the white space processing rules have been
         // applied. The effect of the property on other word-separator characters is undefined."
         // We elect to only space the two required code points.
-        if character == ' ' || character == '\u{a0}' {
-            // https://drafts.csswg.org/css-text-3/#word-spacing-property
-            self.advance += shaping_options.word_spacing;
+        if let Some(word_spacing) = shaping_options.word_spacing {
+            if character == ' ' || character == '\u{a0}' {
+                // https://drafts.csswg.org/css-text-3/#word-spacing-property
+                self.advance += word_spacing;
+            }
         }
     }
 }

components/fonts/lib.rs

@@ -28,9 +28,9 @@ pub use font_store::FontTemplates;
 pub use fonts_traits::*;
 pub(crate) use glyph::*;
 pub use glyph::{GlyphInfo, GlyphStore};
+use icu_locid::subtags::Language;
 pub use platform::font_list::fallback_font_families;
 pub(crate) use shapers::*;
-use style::values::computed::XLang;
 pub use system_font_service::SystemFontService;
 use unicode_properties::{EmojiStatus, UnicodeEmoji, emoji};
 
@@ -47,7 +47,7 @@ pub(crate) enum EmojiPresentationPreference {
 pub struct FallbackFontSelectionOptions {
     pub(crate) character: char,
     pub(crate) presentation_preference: EmojiPresentationPreference,
-    pub(crate) lang: XLang,
+    pub(crate) language: Language,
 }
 
 impl Default for FallbackFontSelectionOptions {
@@ -55,13 +55,13 @@ impl Default for FallbackFontSelectionOptions {
         Self {
             character: ' ',
             presentation_preference: EmojiPresentationPreference::None,
-            lang: XLang::get_initial_value(),
+            language: Language::UND,
         }
     }
 }
 
 impl FallbackFontSelectionOptions {
-    pub(crate) fn new(character: char, next_character: Option<char>, lang: XLang) -> Self {
+    pub(crate) fn new(character: char, next_character: Option<char>, language: Language) -> Self {
         let presentation_preference = match next_character {
             Some(next_character) if emoji::is_emoji_presentation_selector(next_character) => {
                 EmojiPresentationPreference::Emoji
@@ -89,7 +89,7 @@ impl FallbackFontSelectionOptions {
         Self {
             character,
             presentation_preference,
-            lang,
+            language,
         }
     }
 }

components/fonts/platform/freetype/font_list.rs

@@ -19,12 +19,13 @@ use fontconfig_sys::{
     FcPatternDestroy, FcPatternGetInteger, FcPatternGetString, FcResultMatch, FcSetSystem,
 };
 use fonts_traits::{FontTemplate, FontTemplateDescriptor, LocalFontIdentifier};
+use icu_locid::subtags::language;
 use libc::{c_char, c_int};
 use log::debug;
 use servo_base::text::{UnicodeBlock, UnicodeBlockMethod};
 use style::Atom;
 use style::values::computed::font::GenericFontFamily;
-use style::values::computed::{FontStretch, FontStyle, FontWeight, XLang};
+use style::values::computed::{FontStretch, FontStyle, FontWeight};
 use unicode_script::Script;
 
 use crate::font::map_platform_values_to_style_values;
@@ -188,13 +189,13 @@ pub fn fallback_font_families(options: FallbackFontSelectionOptions) -> Vec<&'st
             // In Japanese typography, it is not common to use different fonts
             // for Kanji(Han), Hiragana, and Katakana within the same document.
             // We uniformly fallback to Japanese fonts when the document language is Japanese.
-            _ if options.lang == XLang(Atom::from("ja")) => {
+            _ if options.language == language!("ja") => {
                 families.push("TakaoPGothic");
             },
             _ if matches!(
                 Script::from(options.character),
                 Script::Bopomofo | Script::Han
-            ) && options.lang != XLang(Atom::from("ja")) =>
+            ) && options.language != language!("ja") =>
             {
                 families.push("WenQuanYi Micro Hei");
             },

components/fonts/platform/freetype/mod.rs

@@ -5,7 +5,10 @@
 pub mod font;
 mod freetype_face;
 
-#[cfg(all(target_os = "linux", not(target_env = "ohos"), not(ohos_mock)))]
+#[cfg(any(
+    all(target_os = "linux", not(target_env = "ohos"), not(ohos_mock)),
+    target_os = "freebsd"
+))]
 pub mod font_list;
 
 #[cfg(target_os = "android")]

components/fonts/platform/freetype/ohos/font_list.rs

@@ -3,12 +3,15 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 use std::collections::HashMap;
 use std::ffi::OsStr;
+use std::fs::File;
 use std::os::unix::ffi::OsStrExt;
 use std::path::{Path, PathBuf};
 use std::sync::LazyLock;
 use std::{fs, io};
 
 use log::{debug, error, warn};
+use read_fonts::FileRef::{Collection, Font as OHOS_Font};
+use read_fonts::{FileRef, FontRef, TableProvider};
 use servo_base::text::{UnicodeBlock, UnicodeBlockMethod};
 use style::Atom;
 use style::values::computed::font::GenericFontFamily;
@@ -95,105 +98,59 @@ fn enumerate_font_files() -> io::Result<Vec<PathBuf>> {
     Ok(font_list)
 }
 
-fn detect_hos_font_style(font_modifiers: &[&str]) -> Option<String> {
-    if font_modifiers.contains(&"Italic") {
+fn detect_hos_font_style(font: &FontRef, file_path: &str) -> Option<String> {
+    // This implementation uses the postscript (post) table, which is one of the mandatory tables
+    // according to TrueType's reference manual (https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6.html).
+    // Therefore, raise an error if Fontations fails to read this table for some reason.
+
+    // If angle is 0, then the font style is normal. otherwise, italic.
+    if font
+        .post()
+        .unwrap_or_else(|_| {
+            panic!("Failed to read {:?}'s postscript table!", file_path);
+        })
+        .italic_angle() !=
+        (0 as i32).into()
+    {
         Some("italic".to_string())
     } else {
         None
     }
 }
 
-// Note: The weights here are taken from the `alias` section of the fontconfig.json
-fn detect_hos_font_weight_alias(font_modifiers: &[&str]) -> Option<i32> {
-    if font_modifiers.contains(&"Light") {
-        Some(100)
-    } else if font_modifiers.contains(&"Regular") {
-        Some(400)
-    } else if font_modifiers.contains(&"Medium") {
-        Some(700)
-    } else if font_modifiers.contains(&"Bold") {
-        Some(900)
-    } else {
-        None
+fn detect_hos_font_weight_alias(font: &FontRef) -> Option<i32> {
+    // According to TrueType's reference manual (https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6.html),
+    // os2 is an optional table. Therefore, if Fontations fails to read this table, we don't treat this as an error
+    // and we simply return `None`.
+    match font.os2() {
+        Ok(result) => Some(result.us_weight_class() as i32),
+        Err(_) => None,
     }
 }
 
-fn noto_weight_alias(alias: &str) -> Option<i32> {
-    match alias.to_ascii_lowercase().as_str() {
-        "thin" => Some(100),
-        "extralight" => Some(200),
-        "light" => Some(300),
-        "regular" => Some(400),
-        "medium" => Some(500),
-        "semibold" => Some(600),
-        "bold" => Some(700),
-        "extrabold" => Some(800),
-        "black" => Some(900),
-        _unknown_alias => {
-            warn!("Unknown weight alias `{alias}` encountered.");
-            None
-        },
-    }
-}
-
-fn detect_hos_font_width(font_modifiers: &[&str]) -> FontWidth {
-    if font_modifiers.contains(&"Condensed") {
-        FontWidth::Condensed
-    } else {
-        FontWidth::Normal
-    }
-}
-
-/// Split a Noto font filename into the family name with spaces
-///
-/// E.g. `NotoSansTeluguUI` -> `Noto Sans Telugu UI`
-/// Or for older OH 4.1 fonts: `NotoSans_JP_Bold` -> `Noto Sans JP Bold`
-fn split_noto_font_name(name: &str) -> Vec<String> {
-    let mut name_components = vec![];
-    let mut current_word = String::new();
-    let mut chars = name.chars();
-    // To not split acronyms like `UI` or `CJK`, we only start a new word if the previous
-    // char was not uppercase.
-    let mut previous_char_was_uppercase = true;
-    if let Some(first) = chars.next() {
-        current_word.push(first);
-        for c in chars {
-            if c.is_uppercase() {
-                if !previous_char_was_uppercase {
-                    name_components.push(current_word.clone());
-                    current_word = String::new();
-                }
-                previous_char_was_uppercase = true;
-                current_word.push(c)
-            } else if c == '_' {
-                name_components.push(current_word.clone());
-                current_word = String::new();
-                previous_char_was_uppercase = true;
-                // Skip the underscore itself
+fn detect_hos_font_width(font: &FontRef) -> FontWidth {
+    // According to TrueType's reference manual (https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6.html),
+    // os2 is an optional table. Therefore, if Fontations fails to read this table, we don't treat this as an error
+    // and we simply return `FontWidth::Normal` as a default.
+    match font.os2() {
+        Ok(result) => {
+            let font_width = result.us_width_class().clone();
+            // According to https://learn.microsoft.com/en-us/typography/opentype/spec/os2#uswidthclass,
+            // value between 1 & 4 inclusive represents condensed type.
+            if font_width >= 1 && font_width <= 4 {
+                FontWidth::Condensed
             } else {
-                previous_char_was_uppercase = false;
-                current_word.push(c)
+                FontWidth::Normal
             }
-        }
+        },
+        Err(_) => FontWidth::Normal,
     }
-    if !current_word.is_empty() {
-        name_components.push(current_word);
-    }
-    name_components
 }
 
-/// Parse the font file names to determine the available FontFamilies
-///
-/// Note: For OH 5.0+ this function is intended to only be a fallback path, if parsing the
-/// `fontconfig.json` fails for some reason. Beta 1 of OH 5.0 still has a bug in the fontconfig.json
-/// though, so the "normal path" is currently unimplemented.
-fn parse_font_filenames(font_files: Vec<PathBuf>) -> Vec<FontFamily> {
-    let harmonyos_prefix = "HarmonyOS_Sans";
-
-    let weight_aliases = ["Light", "Regular", "Medium", "Bold"];
-    let style_modifiers = ["Italic"];
-    let width_modifiers = ["Condensed"];
-
+/// This function generates list of `FontFamily` based on font files with the extension `.otf`, `.ttc`, or `.otf`.
+/// If a font file's extension is .ttc, then all the font within it will be processed one by one.
+#[servo_tracing::instrument(skip_all)]
+fn get_system_font_families(font_files: Vec<PathBuf>) -> Vec<FontFamily> {
     let mut families: HashMap<String, Vec<Font>> = HashMap::new();
 
     let font_files: Vec<PathBuf> = font_files
@@ -211,77 +168,36 @@ fn parse_font_filenames(font_files: Vec<PathBuf>) -> Vec<FontFamily> {
         })
         .collect();
 
-    let harmony_os_fonts = font_files.iter().filter_map(|file_path| {
-        let stem = file_path.file_stem()?.to_str()?;
-        let stem_no_prefix = stem.strip_prefix(harmonyos_prefix)?;
-        let name_components: Vec<&str> = stem_no_prefix.split('_').collect();
-        let style = detect_hos_font_style(&name_components);
-        let weight = detect_hos_font_weight_alias(&name_components);
-        let width = detect_hos_font_width(&name_components);
+    let mut all_families = Vec::new();
 
-        let mut name_components = name_components;
-        // If we remove all the modifiers, we are left with the family name
-        name_components.retain(|component| {
-            !weight_aliases.contains(component) &&
-                !style_modifiers.contains(component) &&
-                !width_modifiers.contains(component) &&
-                !component.is_empty()
-        });
-        name_components.insert(0, "HarmonyOS Sans");
-        let family_name = name_components.join(" ");
-        let font = Font {
-            filepath: file_path.to_str()?.to_string(),
-            weight,
-            style,
-            width,
+    for font_file in font_files.iter() {
+        let Ok(font_bytes) =
+            File::open(font_file).and_then(|file| unsafe { memmap2::Mmap::map(&file) })
+        else {
+            continue;
+        };
+        let Ok(file_ref) = FileRef::new(&font_bytes) else {
+            continue;
         };
-        Some((family_name, font))
-    });
 
-    let noto_fonts = font_files.iter().filter_map(|file_path| {
-        let stem = file_path.file_stem()?.to_str()?;
-        // Filter out non-noto fonts
-        if !stem.starts_with("Noto") {
-            return None;
+        match file_ref {
+            OHOS_Font(font) => {
+                if let Some(result) = get_family_name_and_generate_font_struct(&font, &font_file) {
+                    all_families.push(result);
+                }
+            },
+            Collection(font_collection) => {
+                // Process all the font files within the collection one by one.
+                for f in font_collection.iter() {
+                    if let Some(result) =
+                        get_family_name_and_generate_font_struct(&(f.unwrap()), &font_file)
+                    {
+                        all_families.push(result);
+                    };
+                }
+            },
         }
-        // Strip the weight alias from the filename, e.g. `-Regular` or `_Regular`.
-        // We use `rsplit_once()`, since there is e.g. `NotoSansPhags-Pa-Regular.ttf`, where the
-        // Pa is part of the font family name and not a modifier.
-        // There seem to be no more than one modifier at once per font filename.
-        let (base, weight) = if let Some((stripped_base, weight_suffix)) =
-            stem.rsplit_once("-").or_else(|| stem.rsplit_once("_"))
-        {
-            (stripped_base, noto_weight_alias(weight_suffix))
-        } else {
-            (stem, None)
-        };
-        // Do some special post-processing for `NotoSansPhags-Pa-Regular.ttf` and any friends.
-        let base = if base.contains("-") {
-            if !base.ends_with("-Pa") {
-                warn!("Unknown `-` pattern in Noto font filename: {base}");
-            }
-            // Note: We assume here that the following character is uppercase, so that
-            // the word splitting later functions correctly.
-            base.replace("-", "")
-        } else {
-            base.to_string()
-        };
-        // Remove suffixes `[wght]` or `[wdth,wght]`. These suffixes seem to be mutually exclusive
-        // with the weight alias suffixes from before.
-        let base_name = base
-            .strip_suffix("[wght]")
-            .or_else(|| base.strip_suffix("[wdth,wght]"))
-            .unwrap_or(base.as_str());
-        let family_name = split_noto_font_name(base_name).join(" ");
-        let font = Font {
-            filepath: file_path.to_str()?.to_string(),
-            weight,
-            ..Default::default()
-        };
-        Some((family_name, font))
-    });
-
-    let all_families = harmony_os_fonts.chain(noto_fonts);
+    }
 
     for (family_name, font) in all_families {
         if let Some(font_list) = families.get_mut(&family_name) {
@@ -297,6 +213,49 @@ fn parse_font_filenames(font_files: Vec<PathBuf>) -> Vec<FontFamily> {
         .collect()
 }
 
+fn get_family_name_and_generate_font_struct(
+    font_ref: &FontRef,
+    file_path: &PathBuf,
+) -> Option<(String, Font)> {
+    // Parse the file path to string. If this fails, then skip this font.
+    let Some(file_path_string_slice) = file_path.to_str() else {
+        return None;
+    };
+    let file_path_str = file_path_string_slice.to_string();
+
+    // Obtain the font's styling
+    let style = detect_hos_font_style(font_ref, file_path_string_slice);
+    let weight = detect_hos_font_weight_alias(font_ref);
+    let width = detect_hos_font_width(font_ref);
+
+    // Get the family name via the name table. According to TrueType's reference manual (https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6.html),
+    // the name table is a mandatory table. Therefore, if Fontations fails to read this table for whatever reason, return `None` to skip this font altogether.
+    let Ok(font_name_table) = font_ref.name() else {
+        return None;
+    };
+    let Some(family_name) = font_name_table
+        .name_record()
+        .iter()
+        .filter(|record| record.name_id().to_u16() == 1) // According to the reference manual, name identifier code (nameID) `1` is the font family name.
+        .find_map(|record| {
+            record
+                .string(font_name_table.string_data())
+                .ok()
+                .map(|s| s.to_string())
+        })
+    else {
+        return None;
+    };
+
+    let font = Font {
+        filepath: file_path_str,
+        weight,
+        style,
+        width,
+    };
+    Some((family_name, font))
+}
+
 impl FontList {
     fn new() -> FontList {
         FontList {
@@ -309,7 +268,7 @@ impl FontList {
     fn detect_installed_font_families() -> Vec<FontFamily> {
         let mut families = enumerate_font_files()
             .inspect_err(|e| error!("Failed to enumerate font files due to `{e:?}`"))
-            .map(parse_font_filenames)
+            .map(get_system_font_families)
             .unwrap_or_else(|_| FontList::fallback_font_families());
         families.extend(Self::hardcoded_font_families());
         families
@@ -543,20 +502,23 @@ pub fn fallback_font_families(options: FallbackFontSelectionOptions) -> Vec<&'st
             UnicodeBlock::HangulJamoExtendedA |
             UnicodeBlock::HangulJamoExtendedB |
             UnicodeBlock::HangulSyllables => {
-                families.push("Noto Sans CJK");
-                families.push("Noto Serif CJK");
+                families.push("Noto Sans CJK KR");
+                families.push("Noto Sans Mono CJK KR");
+                families.push("Noto Serif CJK KR");
                 families.push("Noto Sans KR");
             },
             UnicodeBlock::Hiragana |
             UnicodeBlock::Katakana |
             UnicodeBlock::KatakanaPhoneticExtensions => {
-                families.push("Noto Sans CJK");
-                families.push("Noto Serif CJK");
+                families.push("Noto Sans CJK JP");
+                families.push("Noto Sans Mono CJK JP");
+                families.push("Noto Serif CJK JP");
                 families.push("Noto Sans JP");
             },
             UnicodeBlock::HalfwidthandFullwidthForms => {
                 families.push("HarmonyOS Sans SC");
-                families.push("Noto Sans CJK");
+                families.push("Noto Sans CJK SC");
+                families.push("Noto Sans Mono CJK SC");
             },
             _ => {},
         }
@@ -590,31 +552,14 @@ mod test {
     use std::path::PathBuf;
 
     #[test]
-    fn split_noto_font_name_test() {
-        use super::split_noto_font_name;
-        assert_eq!(
-            split_noto_font_name("NotoSansSinhala"),
-            vec!["Noto", "Sans", "Sinhala"]
-        );
-        assert_eq!(
-            split_noto_font_name("NotoSansTamilUI"),
-            vec!["Noto", "Sans", "Tamil", "UI"]
-        );
-        assert_eq!(
-            split_noto_font_name("NotoSerifCJK"),
-            vec!["Noto", "Serif", "CJK"]
-        );
-    }
-
-    #[test]
-    fn test_parse_font_filenames() {
-        use super::parse_font_filenames;
-        let families = parse_font_filenames(vec![PathBuf::from("NotoSansCJK-Regular.ttc")]);
+    fn test_get_system_font_families() {
+        use super::get_system_font_families;
+        let families = get_system_font_families(vec![PathBuf::from("NotoSansCJK-Regular.ttc")]);
         assert_eq!(families.len(), 1);
         let family = families.first().unwrap();
         assert_eq!(family.name, "Noto Sans CJK".to_string());
 
-        let families = parse_font_filenames(vec![
+        let families = get_system_font_families(vec![
             PathBuf::from("NotoSerifGeorgian[wdth,wght].ttf"),
             PathBuf::from("HarmonyOS_Sans_Naskh_Arabic_UI.ttf"),
             PathBuf::from("HarmonyOS_Sans_Condensed.ttf"),
@@ -627,34 +572,6 @@ mod test {
         assert_eq!(families.len(), 4);
     }
 
-    #[test]
-    fn test_parse_noto_sans_phags_pa() {
-        use super::parse_font_filenames;
-
-        let families = parse_font_filenames(vec![PathBuf::from("NotoSansPhags-Pa-Regular.ttf")]);
-        let family = families.first().unwrap();
-        assert_eq!(family.name, "Noto Sans Phags Pa");
-    }
-
-    #[test]
-    fn test_old_noto_sans() {
-        use super::parse_font_filenames;
-
-        let families = parse_font_filenames(vec![
-            PathBuf::from("NotoSans_JP_Regular.otf"),
-            PathBuf::from("NotoSans_KR_Regular.otf"),
-            PathBuf::from("NotoSans_JP_Bold.otf"),
-        ]);
-        assert_eq!(families.len(), 2, "actual families: {families:?}");
-        let first_family = families.first().unwrap();
-        let second_family = families.last().unwrap();
-        // We don't have a requirement on the order of the family names,
-        // we just want to test existence.
-        let names = [first_family.name.as_str(), second_family.name.as_str()];
-        assert!(names.contains(&"Noto Sans JP"));
-        assert!(names.contains(&"Noto Sans KR"));
-    }
-
     #[test]
     fn print_detected_families() {
         let list = super::FontList::detect_installed_font_families();

components/fonts/platform/macos/font.rs

@@ -472,17 +472,17 @@ impl Font {
         // the value stored in the HTML lang attribute is a BCP 47 language tag. These two
         // formats are generally compatible, but we may need to make refinements here in
         // the future.
-        let language = CFString::from_str(&options.lang.0);
+        let language = if !options.language.is_empty() {
+            Some(&*CFString::from_str(options.language.as_str()))
+        } else {
+            None
+        };
         let string = CFString::from_str(&options.character.to_string());
         let font = unsafe {
             self.handle.ctfont.for_string_with_language(
                 &string,
                 CFRange::new(0, string.length()),
-                if !options.lang.0.is_empty() {
-                    Some(&*language)
-                } else {
-                    None
-                },
+                language,
             )
         };
 

components/fonts/platform/macos/font_list.rs

@@ -5,6 +5,7 @@
 use std::ffi::c_void;
 
 use fonts_traits::LocalFontIdentifier;
+use icu_locid::subtags::language;
 use log::debug;
 use objc2_core_foundation::{CFDictionary, CFRetained, CFSet, CFString, CFType, CFURL};
 use objc2_core_text::{
@@ -13,7 +14,6 @@ use objc2_core_text::{
 };
 use servo_base::text::{UnicodeBlock, UnicodeBlockMethod, unicode_plane};
 use style::Atom;
-use style::values::computed::XLang;
 use style::values::computed::font::GenericFontFamily;
 use unicode_script::Script;
 
@@ -132,7 +132,7 @@ pub fn fallback_font_families(options: FallbackFontSelectionOptions) -> Vec<&'st
             // In Japanese typography, it is not common to use different fonts
             // for Kanji(Han), Hiragana, and Katakana within the same document. Since Hiragino supports
             // a comprehensive set of Japanese kanji, we uniformly fallback to Hiragino for all Japanese text.
-            _ if options.lang == XLang(Atom::from("ja")) => {
+            _ if options.language == language!("ja") => {
                 families.push("Hiragino Sans");
                 families.push("Hiragino Kaku Gothic ProN");
             },
@@ -141,7 +141,7 @@ pub fn fallback_font_families(options: FallbackFontSelectionOptions) -> Vec<&'st
             // language font to try for fallback is rather arbitrary. Usually, though,
             // we hope that font prefs will have handled this earlier.
             _ if matches!(script, Script::Bopomofo | Script::Han) &&
-                options.lang != XLang(Atom::from("ja")) =>
+                options.language != language!("ja") =>
             {
                 // TODO: Need to differentiate between traditional and simplified Han here!
                 families.push("Songti SC");

components/fonts/platform/mod.rs

@@ -3,32 +3,32 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 #[cfg(all(
-    any(target_os = "linux", target_os = "macos"),
+    any(target_os = "linux", target_os = "macos", target_os = "freebsd"),
     not(target_os = "android"),
     not(target_env = "ohos")
 ))]
 use servo_base::text::{UnicodeBlock, UnicodeBlockMethod};
 #[cfg(all(
-    any(target_os = "linux", target_os = "macos"),
+    any(target_os = "linux", target_os = "macos", target_os = "freebsd"),
     not(target_os = "android"),
     not(target_env = "ohos")
 ))]
 use unicode_script::Script;
 
 #[cfg(all(
-    any(target_os = "linux", target_os = "macos"),
+    any(target_os = "linux", target_os = "macos", target_os = "freebsd"),
     not(target_os = "android"),
     not(target_env = "ohos")
 ))]
 use crate::FallbackFontSelectionOptions;
-#[cfg(any(target_os = "linux", target_os = "android"))]
+#[cfg(any(target_os = "linux", target_os = "android", target_os = "freebsd"))]
 pub use crate::platform::freetype::{font, font_list};
 #[cfg(target_os = "macos")]
 pub use crate::platform::macos::{core_text_font_cache, font, font_list};
 #[cfg(target_os = "windows")]
 pub use crate::platform::windows::{font, font_list};
 
-#[cfg(any(target_os = "linux", target_os = "android"))]
+#[cfg(any(target_os = "linux", target_os = "android", target_os = "freebsd"))]
 pub mod freetype;
 
 #[cfg(target_os = "macos")]
@@ -45,7 +45,7 @@ mod windows {
 }
 
 #[cfg(all(
-    any(target_os = "linux", target_os = "macos"),
+    any(target_os = "linux", target_os = "macos", target_os = "freebsd"),
     not(target_os = "android"),
     not(target_env = "ohos")
 ))]

components/fonts/tests/font.rs

@@ -77,7 +77,7 @@ fn test_font_can_do_fast_shaping() {
     // Fast shaping requires a font with a kern table and no GPOS or GSUB tables.
     let shaping_options = ShapingOptions {
         letter_spacing: None,
-        word_spacing: Au::zero(),
+        word_spacing: None,
         script: Script::Latin,
         language: Language::UND,
         flags: ShapingFlags::empty(),
@@ -88,7 +88,7 @@ fn test_font_can_do_fast_shaping() {
     // Non-Latin script should never have fast shaping.
     let shaping_options = ShapingOptions {
         letter_spacing: None,
-        word_spacing: Au::zero(),
+        word_spacing: None,
         script: Script::Cherokee,
         language: Language::UND,
         flags: ShapingFlags::empty(),
@@ -99,7 +99,7 @@ fn test_font_can_do_fast_shaping() {
     // Right-to-left text should never use fast shaping.
     let shaping_options = ShapingOptions {
         letter_spacing: None,
-        word_spacing: Au::zero(),
+        word_spacing: None,
         script: Script::Latin,
         language: Language::UND,
         flags: ShapingFlags::RTL_FLAG,

components/fonts/tests/font_context.rs

@@ -21,6 +21,7 @@ mod font_context {
         PlatformFontMethods, SystemFontServiceMessage, SystemFontServiceProxy,
         SystemFontServiceProxySender, fallback_font_families,
     };
+    use icu_locid::subtags::Language;
     use net_traits::{ResourceThreads, start_fetch_thread};
     use paint_api::CrossProcessPaintApi;
     use parking_lot::Mutex;
@@ -30,7 +31,6 @@ mod font_context {
     use style::computed_values::font_optical_sizing::T as FontOpticalSizing;
     use style::properties::longhands::font_variant_caps::computed_value::T as FontVariantCaps;
     use style::properties::style_structs::Font as FontStyleStruct;
-    use style::values::computed::XLang;
     use style::values::computed::font::{
         FamilyName, FontFamily, FontFamilyList, FontFamilyNameSyntax, FontStretch, FontStyle,
         FontSynthesis, FontWeight, SingleFontFamily,
@@ -264,7 +264,7 @@ mod font_context {
         let group = context.context.font_group(ServoArc::new(style));
 
         let font = group
-            .find_by_codepoint(&mut context.context, 'a', None, XLang::get_initial_value())
+            .find_by_codepoint(&mut context.context, 'a', None, Language::UND)
             .unwrap();
         assert_eq!(&font_face_name(&font.identifier()), "csstest-ascii");
         assert_eq!(
@@ -277,7 +277,7 @@ mod font_context {
         );
 
         let font = group
-            .find_by_codepoint(&mut context.context, 'a', None, XLang::get_initial_value())
+            .find_by_codepoint(&mut context.context, 'a', None, Language::UND)
             .unwrap();
         assert_eq!(&font_face_name(&font.identifier()), "csstest-ascii");
         assert_eq!(
@@ -290,7 +290,7 @@ mod font_context {
         );
 
         let font = group
-            .find_by_codepoint(&mut context.context, 'á', None, XLang::get_initial_value())
+            .find_by_codepoint(&mut context.context, 'á', None, Language::UND)
             .unwrap();
         assert_eq!(&font_face_name(&font.identifier()), "csstest-basic-regular");
         assert_eq!(
@@ -313,7 +313,7 @@ mod font_context {
         let group = context.context.font_group(ServoArc::new(style));
 
         let font = group
-            .find_by_codepoint(&mut context.context, 'a', None, XLang::get_initial_value())
+            .find_by_codepoint(&mut context.context, 'a', None, Language::UND)
             .unwrap();
         assert_eq!(
             &font_face_name(&font.identifier()),
@@ -322,7 +322,7 @@ mod font_context {
         );
 
         let font = group
-            .find_by_codepoint(&mut context.context, 'á', None, XLang::get_initial_value())
+            .find_by_codepoint(&mut context.context, 'á', None, Language::UND)
             .unwrap();
         assert_eq!(
             &font_face_name(&font.identifier()),

components/hyper_serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "servo-hyper-serde"
-version = "0.13.2"
+version.workspace = true
 edition.workspace = true
 authors = ["The Servo Project Developers"]
 description = "Serde support for hyper types."

components/layout/Cargo.toml

@@ -19,6 +19,7 @@ doctest = false
 tracing = ["dep:tracing"]
 
 [dependencies]
+accesskit = { workspace = true }
 app_units = { workspace = true }
 atomic_refcell = { workspace = true }
 bitflags = { workspace = true }
@@ -27,8 +28,9 @@ embedder_traits = { workspace = true }
 euclid = { workspace = true }
 fonts = { workspace = true }
 fonts_traits = { workspace = true }
-html5ever = { workspace = true }
+web_atoms = { workspace = true }
 icu_locid = { workspace = true }
+icu_properties = { workspace = true, features = ["compiled_data"] }
 icu_segmenter = { workspace = true }
 itertools = { workspace = true }
 kurbo = { workspace = true }
@@ -46,6 +48,7 @@ rustc-hash = { workspace = true }
 script = { workspace = true }
 script_traits = { workspace = true }
 selectors = { workspace = true }
+serde = { workspace = true }
 servo_arc = { workspace = true }
 servo-base = { workspace = true }
 servo-config = { workspace = true }
@@ -64,7 +67,6 @@ unicode-script = { workspace = true }
 unicode_categories = { workspace = true }
 url = { workspace = true }
 webrender_api = { workspace = true }
-xi-unicode = { workspace = true }
 
 [dev-dependencies]
 num-traits = { workspace = true }