Make TransformState::Move accumulate into existing transform more often. #30492
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The substantive change here is the removal of the test of accumulating_transform_ in TransformState::Move. At least when direction_ is kApplyTransformDirection, optimizing away the modification to the existing transform into a move is not safe. The remainder of the code changes are removing accumulating_transform_, since its remaining uses are all in DCHECK()s and its meaning is somewhat unclear. It's not clear whether it's intended to be an indicator for whether accumulated_transform_ would be non-null were it not for the caching optimization in TransformState::FlattenWithTransform, or whether it's an indication of the state of flattening or preserve-3d. Without the code change here, virtual/transform-interop-disabled/external/wpt/css/css-transforms/transform-getBoundingClientRect-001.html fails (with 75 rather than 125), but external/wpt/css/css-transforms/transform-getBoundingClientRect-001.html passes both with and without the change. Bug: 1247858 Change-Id: Id32a11b2bf66757b0dbbab251c598222f9d120a7 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3152179 Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org> Commit-Queue: David Baron <dbaron@chromium.org> Cr-Commit-Position: refs/heads/main@{#920070}
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The substantive change here is the removal of the test of
accumulating_transform_ in TransformState::Move. At least when
direction_ is kApplyTransformDirection, optimizing away the modification
to the existing transform into a move is not safe.
The remainder of the code changes are removing accumulating_transform_,
since its remaining uses are all in DCHECK()s and its meaning is
somewhat unclear. It's not clear whether it's intended to be an
indicator for whether accumulated_transform_ would be non-null were it
not for the caching optimization in
TransformState::FlattenWithTransform, or whether it's an indication of
the state of flattening or preserve-3d.
Without the code change here,
virtual/transform-interop-disabled/external/wpt/css/css-transforms/transform-getBoundingClientRect-001.html
fails (with 75 rather than 125), but
external/wpt/css/css-transforms/transform-getBoundingClientRect-001.html
passes both with and without the change.
Bug: 1247858
Change-Id: Id32a11b2bf66757b0dbbab251c598222f9d120a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3152179
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: David Baron <dbaron@chromium.org>
Cr-Commit-Position: refs/heads/main@{#920070}