commit d39e90e1eb0425817873502607ced0e0a2f2cee1
author Xianzhu Wang <wangxianzhu@chromium.org> Tue Aug 04 17:07:16 2020
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> Tue Aug 04 17:26:56 2020
tree cc0986da0fa8a95b2c6de4a4170d6959ec33bdfe
parent 165d371ce40f9cf8565e82c07c8f0fd6af5f7ef3

Revert "Reland "Use border box or layout overflow rect for layout shift tracking""

This reverts commit 84b0d04040453e3f56381655d68909afcc90e6d6.

Reason for revert: Caused crbug.com/1112642.

Original change's description:
> Reland "Use border box or layout overflow rect for layout shift tracking"
>
> This reverts commit 491b5a9cbe75eb9cdde6e9e0b21e8246f441b086.
>
> The original CL was reverted because it caused failure on MSAN bots
> due to use of uninitialized value.
>
> The reason was that PaintInvalidatorContext::tree_builder_context_
> pointed into an PrePaintTreeWalkContext entry in a vector, and the
> vector could be reallocated when we added new entries, causing the
> pointer in the parent PaintInvalidatorContext to point to an invalid
> address.
>
> Now remove PaintInvalidatorContext::tree_builder_context_ and add
> PaintInvalidatorContext::transform_ (which was the only used information
> from the parent PaintInvalidatorContext) to avoid the problem.
>
> Original change's description:
> > Revert "Use border box or layout overflow rect for layout shift tracking"
> >
> > This reverts commit 0933392f84b4bb96466bd86c0e814d96f63ba137.
> >
> > Reason for revert: ASAN/MSAN failures due to "use of uninitialized value"; see e.g. https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8873209606965810848/+/steps/browser_tests/0/logs/Deterministic_failure:_AllForms__x2f_FormStructureBrowserTest.DataDrivenHeuristics__x2f_148__status_FAILURE_/0
> >
> > Original change's description:
> > > Use border box or layout overflow rect for layout shift tracking
> > >
> > > This CL addresses the following issues of layout shift tracking:
> > > - Changed visual overflows triggered layout shift report
> > >   (originally filed as crbug.com/1090763).
> > > - Descendant layout overflows were not included in ancestor's layout
> > >   shift report.
> > > - Unnecessary descendant layout shift report.
> > > - Slow visual rect calculation for LayoutInline and LayoutText.
> > >
> > > It includes the following changes
> > > - Track LayoutBoxes and LayoutTexts only.
> > > - Track both old and new starting points and visual representations
> > >   instead of using location of visual rects as starting points.
> > > - For a LayoutBox, the local visual representation is the layout
> > >   overflow rect if the LayoutBox has layout overflow and doesn't clip
> > >   overflow. Otherwise use the border box rect.
> > > - For a LayoutText, suppose its shift causes shift of all contents
> > >   in containing block logically below the LayoutText, and use that
> > >   part of visual representation of the containing block as the visual
> > >   representation of the shift.
> > > - Map both local starting points and local visual representations to
> > >   the initial containing block and viewport.
> > >
> > > This has the following benefits:
> > > - More accurate starting points and visual representations, conforming
> > >   to the specs;
> > > - Better performance by
> > >   * avoiding unnecessary layout shift reports of descendants
> > >   * avoiding slow LayoutInline and LayoutText visual rect calculation.
> > > - sizeof(LayoutObject) is reduced by 16 bytes because now we use the
> > >   previous geometry data in LayoutBoxes for paint invalidation.
> > >
> > > Bug: 1108622
> > > Change-Id: I7ebb4e250e7ca2a03b4dadea50034e300e55ad84
> > > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2319538
> > > Reviewed-by: Steve Kobes <skobes@chromium.org>
> > > Reviewed-by: Koji Ishii <kojii@chromium.org>
> > > Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#793806}
> >
> > TBR=wangxianzhu@chromium.org,skobes@chromium.org,kojii@chromium.org
> >
> > Change-Id: I590f2abc4a48ba65bdfe7a948ffce00b299f9e06
> > No-Presubmit: true
> > No-Tree-Checks: true
> > No-Try: true
> > Bug: 1108622
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2333578
> > Reviewed-by: Peter Kasting <pkasting@chromium.org>
> > Commit-Queue: Peter Kasting <pkasting@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#793874}
>
> # Not skipping CQ checks because this is a reland.
>
> Bug: 1108622
> Change-Id: I253a24799b6d2a3af346d4f65e3889217064b035
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2333648
> Reviewed-by: Philip Rogers <pdr@chromium.org>
> Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#794218}

TBR=wangxianzhu@chromium.org,pdr@chromium.org

Change-Id: I06c05f8cab6b2cc2ecd3cf3febf930e6eb95f777
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1108622, 1112642
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2336782
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#794567}