This bug will track how CSS that has both scrollbar-width (and probably in future scrollbar-color) and ::-webkit-scrollbar styles works. Chromiums implementation makes the standard properties take precedence over the legacy pseudos so this behaviour should be matched.
<rdar://problem/109905135>
Pull request: https://github.com/WebKit/WebKit/pull/14440
Committed 265129@main (964948660ae0): <https://commits.webkit.org/265129@main> Reviewed commits have been landed. Closing PR #14440 and removing active labels.