Bug 1832047 [wpt PR 39901] - Pre-paint: Use ancestor fragments when walking a missed...

Bug 1832047 [wpt PR 39901] - Pre-paint: Use ancestor fragments when walking a missed child., a=testonly

Automatic update from web-platform-tests
Pre-paint: Use ancestor fragments when walking a missed child.

Find and use the right fragments for ancestors between the containing
block (fragmentainer) and the missed OOF descendant, when possible.

There are cases where we miss an OOF child, but still have some of the
ancestors represented in the current fragmentainer. We need to find
them, so that we can use the correct paint offset and size.

The clipping issues mentioned in crbug.com/1442211 will be dealt with in
a follow-up CL. We still don't apply any clipping on ancestors when
walking a missed child.

Bug: 1442211
Change-Id: I4fcb0e7260829070d6a5f66f6785b3897fb00f90
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4513908
Reviewed-by: Alison Maher <almaher@microsoft.com>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1142377}

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wpt-commits: 06c34efac3bd23bf49660d07cd88db2b97d75a96
wpt-pr: 39901