1878726 - [wpt-sync] Sync PR 44402 - [HitTestTransparency] Experimental status

Status: RESOLVED FIXED

(Core :: DOM: Events, task, P4)

Description

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

Sync web-platform-tests PR 44402 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/44402
Details from upstream follow.

Xianzhu Wang <[e-mail]> wrote:

[HitTestTransparency] Experimental status

The feature uses cc::HitTestOpacity::kTransparent for pointer-events:
none. The flag is first marked on paint chunks, then PendingLayer and
cc::Layer, by merging cc::HitTestOpacity from merged painted results.
The merge algorithm (which is already ready for HitTestOpaqueness)
can handle cases such as pointer-events:none with pointer-events:auto
descendants (which will be merged into cc::HitTestOpaqueness::kMixed).
cc::Layer::HitTestable() is now based on this flag for blink.

For test coverage, this CL also includes changes to make existing
tests pass or fix existing bugs with the feature:

• LayerTreeHostImpl::BuildHitTestData() now handles a SurfaceLayer
  with pointer-events:none even if it doesn't draw contents, to make
  CrossSiteSubframe/DragAndDropBrowserTest.CrossTabDrag/* pass.
• Correct hit test transparency for scrolling contents.
• Correct hit test transparency for frames under pointer-events:none
  container (b/323688987).
• New tests.

ClusterTelemetry job shows that it can reduce main thread scrolling (hit test or repaint) by 36% (kFailedHitTest by 40%,
kNonFastScrollableRegion by 67%) compared to HitTestOpaqueness only.

Bug: b/40062957, b/323688987
Change-Id: I224c8e5f047ec27bf4c8957ae59643457cc9252e

Reviewed-on: https://chromium-review.googlesource.com/5263065
WPT-Export-Revision: 699f42c86445658e1d439480c3db32ba1c173d9e

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=fa360c910f45b7fd830abded907625210f019564

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 6 tests and 1 subtests

Status Summary

Firefox

OK : 6
PASS: 6

Chrome

OK : 6
PASS: 5
FAIL: 1

Safari

OK : 6
PASS: 5
FAIL: 1

Links

Gecko CI (Treeherder)
GitHub PR Head
GitHub PR Base

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5bcae2277df2
[wpt PR 44402] - [HitTestTransparency] Experimental status, a=testonly

Comment 4

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/5bcae2277df2