In a scrollable main frame PDF, the scrollbar does not grow when hovered, and you can’t click and drag on the thumb to scroll.
<rdar://124785551>
Pull request: https://github.com/WebKit/WebKit/pull/26011
Committed 276244@main (5dce1764e0a3): <https://commits.webkit.org/276244@main> Reviewed commits have been landed. Closing PR #26011 and removing active labels.