This adds support for viewing request payloads (POST data) and response
bodies in the Firefox DevTools network panel.
Request bodies are captured when network requests start and passed
through IPC to the NetworkEventActor, which returns them via the
getRequestPostData protocol method.
Response bodies are streamed via a new IPC message as data is received,
accumulated in NetworkEventActor (with a 10MB size limit to prevent
memory issues), and returned via getResponseContent. Text content is
returned as UTF-8, while binary content (images, etc.) is base64.
Previously, console messages were sent using an index-based system where
DevTools would be notified of new message indices and then request them
in batches. This created synchronization issues during page navigation
when the WebContent process resets while DevTools still has stale index
state.
This changes to a push-based model where console messages are sent
immediately as resources when they are logged, matching how Firefox
DevTools handles console messages. Each message is pushed through IPC
and forwarded to DevTools as a "console-message" or "error-message"
resource.
This eliminates the need for index tracking in FrameActor and simplifies
the entire console message pipeline from WebContent through to DevTools.
When a page navigates, send document-event resources with
"will-navigate" and tabNavigated messages so Firefox DevTools
can follow along and clear the Network panel appropriately.
Hook ResourceLoader to emit network request lifecycle events through
IPC to the UI process, where FrameActor creates NetworkEventActor
instances that serialize requests using Firefox's Remote Debug Protocol.
The Network panel now shows requests with method, URL, status, MIME
type, size, and timing information. Several features remain stubbed
(POST data, response content, cause detection) marked with FIXMEs.
This is enough for Firefox to display the Accessibility tab, containing
our accessibility tree which can be inspected. Most information is
blank for now.
There's quite a bit of duplication between AccessibilityWalkerActor and
WalkerActor - it might be worth trying to make a base class once the
details are figured out. Frustratingly, the two don't work quite the
same: for a lot of messages that would be sent to WalkerActor, the
accessibility equivalent is sent to the AccessibilityNodeActor instead.
Co-authored-by: Tim Flynn <trflynn89@pm.me>
This is to prepare for an upcoming change where we will need to track
replies to messages by ID. We will be able to add parameters to this
structure without having to edit every single actor subclass header
file.
There is a lot needed all at once to actually inspect a tab's DOM tree.
It begins with requesting a "watcher" from a TabActor. It seems there
can be many types of watchers, but here we implement the "frame" watcher
only. The watcher creates an "inspector", which in turn creates a
"walker", which is the actor ultimately responsible for serializing and
inspecting the DOM tree.
In between all that, the DevTools client will send a handful of other
informational requests. If we do not reply to these, the client will not
move forward with the walker. For example, the CSSPropertiesActor will
be asked for a list of all known CSS properties.
