web-platform-tests/wpt merge_pr_48827

on GitHub

[reading-flow] Implement tabindex behavior

Per explainer [1], we update the reading-flow scope tabindex behavior:

1. On the "reading flow items", tabindex is ignored for ordering
   purposes.
   1. If tabindex is higher than 0, adjust it to 0 for scoped focus
      navigation purposes.
2. On the descendants of the "reading flow items", tabindex's ordering
   behavior is scoped to that reading flow item subtree.
   1. The reading flow items are scope owners.

[1] https://github.com/dizhang168/reading-flow/blob/main/reading-flow-vs-tabindex.md

We also remove the helper functions NextReadingFlowItem and
PreviousReadingFlowItem because the spec rules above simplify the
reading flow scope traversal and we do not need to visit descendants.

Change-Id: Ie1f24685d1b38fd64d06dc7d7945bb476d636f7a
Bug: 371024056
Bug: 40932006
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5950103
Reviewed-by: Mason Freed masonf@chromium.org
Commit-Queue: Di Zhang dizhangg@chromium.org
Cr-Commit-Position: refs/heads/main@{#1374224}