2024939 - [wpt-sync] Sync PR 58544 - layout: Fix `first-paint` detection

Status: RESOLVED FIXED

(Core :: DOM: Performance APIs, task, P4)

Description

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

Sync web-platform-tests PR 58544 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/58544
Details from upstream follow.

Shubham Gupta <[e-mail]> wrote:

layout: Fix first-paint detection

This PR comprises

1. Segregate paintable and contentful.
2. Adds Checking of non-default background for eligibility to mark first-paint.
3. Adds a bool is_paintable to display_list and use same for marking first-paint.

TODO: This doesn't consider iframes. Will add PR after fixing WPT tests.

Raised an issue for some incomplete definitions: https://github.com/w3c/paint-timing/issues/122

Testing:

• wpt/tests/paint-timing/first-paint-only/first-paint-bg-color.html
• Updated WPT tests expectations.
  • wpt/paint-timing/first-image-child.html
  • wpt/paint-timing/first-paint-only/sibling-painting-first-image.html
• Unit Test: servo/tests/performance_paint_timings.rs. Following Tests Cases are covered:

Background Pref	Root Background	FP	TC
Default	Unset	:x:	test_default_pref_with_unset_background
Non-Default	Unset	:x:	test_non_default_pref_with_unset_background
Default	Transparent	:x:	test_default_pref_with_transparent_background
Non-Default	Unset	:x:	test_non_default_pref_with_transparent_background
Default	Set	:white_check_mark:	test_default_pref_with_background
Non-Default	Set	:white_check_mark:	test_non_default_pref_with_background
Non-Default	Set (same as pref)	:x:	test_non_default_pref_with_same_background

Fixes: #<!-- nolink -->42148

Reviewed in servo/servo#42975

Comment 1

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

Pushed to try (stability) https://treeherder.mozilla.org/#/jobs?repo=try&revision=61fe7657bf89b08ae7ecff38b349ce09feb912f3

Comment 2

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

CI Results

Ran 9 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 4 tests

Status Summary

Firefox

OK : 1
FAIL: 1

Chrome

OK : 1
FAIL: 1

Safari

OK : 1
FAIL: 1

Links

Gecko CI (Treeherder)
GitHub PR Head
GitHub PR Base

Details

New Tests That Don't Pass

• /paint-timing/first-paint-only/child-painting-first-image.html [wpt.fyi]: SKIP
• /paint-timing/first-paint-only/first-paint-bg-color.html [wpt.fyi]: OK [GitHub], SKIP [Gecko-android-em-14-x86_64-debug-geckoview, Gecko-android-em-14-x86_64-lite-opt-geckoview, Gecko-android-em-14-x86_64-opt-geckoview, Gecko-linux2404-64-debug, Gecko-linux2404-64-opt, Gecko-windows11-32-24h2-debug, Gecko-windows11-32-24h2-opt, Gecko-windows11-64-24h2-debug, Gecko-windows11-64-24h2-opt] (Chrome: OK, Safari: OK)
  • First paint fires due to background color. No FCP: FAIL (Chrome: FAIL, Safari: FAIL)
• /paint-timing/first-paint-only/first-paint-only.html [wpt.fyi]: SKIP
• /paint-timing/first-paint-only/sibling-painting-first-image.html [wpt.fyi]: SKIP

Tests Disabled in Gecko Infrastructure

• /paint-timing/first-paint-only/child-painting-first-image.html [wpt.fyi]: SKIP
• /paint-timing/first-paint-only/first-paint-bg-color.html [wpt.fyi]: OK [GitHub], SKIP [Gecko-android-em-14-x86_64-debug-geckoview, Gecko-android-em-14-x86_64-lite-opt-geckoview, Gecko-android-em-14-x86_64-opt-geckoview, Gecko-linux2404-64-debug, Gecko-linux2404-64-opt, Gecko-windows11-32-24h2-debug, Gecko-windows11-32-24h2-opt, Gecko-windows11-64-24h2-debug, Gecko-windows11-64-24h2-opt] (Chrome: OK, Safari: OK)
• /paint-timing/first-paint-only/first-paint-only.html [wpt.fyi]: SKIP
• /paint-timing/first-paint-only/sibling-painting-first-image.html [wpt.fyi]: SKIP

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/47b2f49b7738
https://hg.mozilla.org/integration/autoland/rev/46542fcc17a8
[wpt PR 58544] - layout: Fix `first-paint` detection, a=testonly

Comment 4

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/46542fcc17a8