CSSFontFaceRule inherited from CSSStyleSheet::Subresource, which made
each face a critical subresource of its parent stylesheet. New
subresources start in the Unloaded state, and the stylesheet's
loading_state() treats Unloaded as Loading.
When a @font-face declares a unicode-range and no codepoint in that
range is ever rendered, FontComputer only registers the face for
matching and never calls FontFace::load() on it. The face stays
Unloaded, so the parent stylesheet stays stuck reporting Loading,
which keeps HTMLLinkElement's load-event delayer alive and prevents
the document load event from firing. HTMLParserEndState then times
out in phase 2 (WaitingForLoadEventDelay) after 15 seconds.
Decouple @font-face from the stylesheet's loading state. Font loading
remains tracked by FontFaceSet, which is the correct place.
The spec states that updates to descriptors in a `@font-face` rule
should be reflected in the connected `FontFace`'s attributes.
Previously this was achieved by directly accessing those descriptors
when calling the attribute getters, but this has a couple of issues:
a) The changes are only reflected if we use the accessors (i.e.
`FontFace::family()` rather than `FontFace::m_family`) which isn't
the case everywhere
b) The changes aren't persisted after the `FontFace` is disconnected
from it's `CSSFontFaceRule`
To fix these issues we now reparse and store the `FontFace`'s attributes
whenever the `CSSFontFaceRule`'s descriptors change.
Having the dumping code in a separate Dump.cpp meant that it was often
overlooked when the rules gained new features, and also limits dumping
to publicly-accessible information.
CSSFontFaceRule now stores its values as a CSSFontFaceDescriptors, with
a ParsedFontFace produced on request. This is exposed via the `style`
attribute, so we pass a lot of tests that try to read values from
that.
We have one test regression, which we passed by mistake before: The test
wanted to ensure we don't allow `@font-face` nested inside other rules.
We passed it just because we discarded any `@font-face` without a
`font-family`. What we're supposed to do is 1) keep at-rules with
missing required descriptors and just not use them, and 2) reject
certain ones when nested.
We may want to cache the ParsedFontFace in the future, but I didn't here
because 1) it's called rarely, and 2) that would mean knowing to
invalidate it when the CSSFontFaceDescriptors changes, which isn't
obvious to me right now.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
