tree a9edd7c9c11d2d958f451efa38ce76512f21b5dc
parent dfd29f2d2b7e9ff515fa948d7733c36721d04285
author Xianzhu Wang <wangxianzhu@chromium.org> 1608142725 -0800
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> 1608144097 -0800

Ignore layout shift when visibility:hidden becomes visible

We should ignore layout shift if the object was ineligible for layout
shift tracking during the previous paint invalidation. Add
LayoutObject::ShouldSkipNextLayoutShiftTracking() and set it during
paint invalidation if the object is ineligible for layout shift
tracking. In the next paint invalidation, if the flag is true, skip
layout shift tracking and reset the flag.

This also applies to content-visibility:auto for which we cleared
LayoutBox's previous size to prevent layout shift tracking for the next
cycle. The new flag is basically equivalent to the old method, but also
covers more cases, e.g. the old method would fail if the object had
visual overflow because PreviousPhysicalVisualOverflowRect() was not
based on PreviousSize() and empty.

Bug: 1152869
Change-Id: I000489dd8093dab8d2ab3605ad4ce3bd39fd11b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2591367
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837627}