VT: Ensure view-transition-names are tree scoped.
This only changes vt name discovery to match the scope of the
originating element (document). The presence of vt names still causes
things like stacking context, which I think is correct.
Bug: 339438836
Change-Id: I47d3d1d78ca4938f259841ea04ab4b0b472914c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5531882
Reviewed-by: Khushal Sagar khushalsagar@chromium.org
Commit-Queue: Vladimir Levin vmpstr@chromium.org
Cr-Commit-Position: refs/heads/main@{#1299414}