https://drafts.csswg.org/css-overflow/#scrollbar-gutter-property Property syntax is auto | stable && both-edges?
<rdar://problem/109771936>
Pull request: https://github.com/WebKit/WebKit/pull/14314
Committed 264568@main (1232ab0a27b7): <https://commits.webkit.org/264568@main> Reviewed commits have been landed. Closing PR #14314 and removing active labels.