Bug 1598794 [wpt PR 20413] - Don't enqueue a scroll event for clampin…

…g or anchoring scrolls if not changed., a=testonly

Automatic update from web-platform-tests
Don't enqueue a scroll event for clamping or anchoring scrolls if not changed.

Other scroll types will still directly enqueue a scroll event.

Forced layouts may cause scroll offset changes that are undone
by later updates.

There is no spec that requires the current behavior as far as I can
tell. The CSSOM spec calls out that it should fire "when the viewport
or element is scrolled" [1]

[1] https://drafts.csswg.org/cssom-view/#eventdef-document-scroll

Bug: 988991

Change-Id: I4e4ebcf2c5bcba8111d73ebd0b2b8a037034caaa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1928243
Reviewed-by: Nick Burris <nburrischromium.org>
Reviewed-by: David Bokan <bokanchromium.org>
Commit-Queue: Chris Harrelson <chrishtrchromium.org>
Cr-Commit-Position: refs/heads/master{#721247}

--

wpt-commits: f05d61183a22708b4aa4a0c57bd06bab813cb0ec
wpt-pr: 20413

UltraBlame original commit: 015d75b07dd8f355e2540830a52ef52fcaecf203

testing/web-platform/tests/html/interaction/focus/the-autofocus-attribute/update-the-rendering.html

@@ -273,6 +273,14 @@
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+requestAnimationFrame
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@@ -317,6 +325,7 @@
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