merge_pr_50239

[carousel] Support user action pseudos after Carousel pseudo elements

This CL allows user action pseudo classes (e.g. :hover) to be used after
Carousel pseudo elements (::scroll-marker and ::scroll-button)
selectors.

Bug: 388545121
Change-Id: I1c944673c9e0f6624a71a77ad657f79e3c140373
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6182565
Commit-Queue: Daniil Sakhapov [email protected]
Reviewed-by: Rune Lillesveen [email protected]
Cr-Commit-Position: refs/heads/main@{#1410241}