1564747 - [wpt-sync] Sync PR 17610 - Reland "Fix first line style caching issues"

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, task, P4)

Description

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Sync web-platform-tests PR 17610 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/17610
Details from upstream follow.

Xianzhu Wang <[e-mail]> wrote:

Reland "Fix first line style caching issues"

This is a reland of 228ee33446fc20cef8fcc94503a91c16bbcfc6fb

Compared to the original CL, this relanded (again) CL has the
following changes:

• Remove the lazy update of first line image observers which was not
  needed and didn't work (causing reentrancy of
  UpdateFirstLineImageObservers),
• In LayoutObject::UpdateFirstLineImageObservers(), hold the first
  line style's reference locally because UpdateImageObservers may
  call LayoutBlockFlow::ImageChanged() which invalidates the cached
  first line style.

Original change's description:

Fix first line style caching issues

1. Cache conflict issue:

Previously calls to Element:: Element::CachedStyleForPseudoElement()
with different second parameters caused cache conflict. The second
call to it might get unwanted result that was cached with a different
second parameter.

Now remove the second parameter, and the function gets and caches the
pseudo style only based on its own computed style. If a caller wants
a pseudo style based on another style, the caller should call
Element::UncachedStyleForPseudoElement() and manage cache by itself.

2. Under-invalidation on change

Cached first line style needs invalidation in two cases:
a) when the ::first-line style changes, we should invalidate all
cached first line styles affected.
b) when style of an inline element (which inherits ::first-line
style) changes, as the inline element's style has higher priority
than the inherited ::first-line style, even if the style doesn't
change, we need to invalidate the cached
kPseudoIdFirstLineInherited style if the new style is different
from the inherited ::first-line style.

Bug: 979054

Change-Id: Icffe68d5136349d12cce6e92d1d3bf153c28903a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1678878
Reviewed-by: Rune Lillesveen \<[e-mail]>
Commit-Queue: Xianzhu Wang \<[e-mail]>
Cr-Commit-Position: refs/heads/master@{#673574}

Bug: 979054
Change-Id: If7211c585df77964789140277839a8f1c3822a15
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1685672
Commit-Queue: Xianzhu Wang \<[e-mail]>
Reviewed-by: Fredrik Söderquist \<[e-mail]>
Cr-Commit-Position: refs/heads/master@{#674509}

Comment 1

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Pushed to try https://treeherder.mozilla.org/#/jobs?repo=try&revision=29b3a31b5c532b4e5de5be283ce69889a251c6c8

Comment 2

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Pushed to try (stability) https://treeherder.mozilla.org/#/jobs?repo=try&revision=666a9dd2824a52fbfaeb2b37c6423a76fa17ade7

Comment 3

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Failed to get results from try push

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/9a057a0ac00f
[wpt PR 17610] - Reland "Fix first line style caching issues", a=testonly

Comment 5

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/9a057a0ac00f