commit eca3b65cd6ad76cd16d9dac97ef33b241c59cd12
author Anders Hartvoll Ruud <andruud@chromium.org> Tue Jun 11 10:59:18 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Jun 11 10:59:18 2024
tree 91f3d5d1b28d0deb48060ab2441df69577611c93
parent 95bb92263bc73ae9a445bf1c951bb13d4fc41f5b

[anchor] Update OOF style correctly when nothing fits

We currently have a bug when updating the OOF style for an element
that:

 * Does not contain any anchor*() functions (or similar).
 * Has an overflowing base style.
 * Has at least one item in position-try-options, all of which overflow.

In the above case, neither the base attempt nor the position-try-option
attempts are successfully placed within the CB, and during OOF style
iteration (OOFCandidateStyleIterator) we then go back to the base
styles. The problem is that this we'll then call UpdateStyleForOutOfFlow
with try_set=nullptr and tactic_list=<empty>, which (absent any anchor()
queries) causes the current logic to think that no update is needed.
However, the ComputedStyle currently held by the element is the style
from the last (failed) position-try attempt, so an update *is* needed
if we want to back to base.

To fix this:

 * A call to UpdateStyleForOutOfFlow is now unconditional.
   It will always recalculate the style.
 * When OOFCandidateStyleIterator is initialized, we check if
   we depend on anchor*() queries, and if so update the style.
   This initialization is reached by all OOFs, not just those that
   use anchor positioning features.
 * All other calls to UpdateStyle in OOFCandidateStyleIterator
   will always lead to a style recalc. That's because these calls only
   take place when there's some position-try-option being processed,
   which are exactly the cases where we always need to recalc the style.

Fixed: 339686368
Change-Id: I046e20527e29924d8b6fbbd794232f51b7a2bb59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5616572
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1313301}