Avoid marking ancestor layout objects during pre-paint.

If we really need to mark an object for paint invalidation checking
during pre-paint, stay away from the ancestors, since we might already
be done with them, and therefore end up leaving them dirty "forever".

Even if they are ancestors, LayoutObject-tree-wise, it doesn't have to
mean that are ancestors in the physical fragment tree.

Bug: 1451185
Change-Id: I9fef344619cfe6a99d80dd49e904fd41dd464167
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4755525


Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1180434}