Scroll To Text Fragement re-flashes after every dynamic style sheet load, and fights user scrolls to do so.
<rdar://problem/112608578>
Pull request: https://github.com/WebKit/WebKit/pull/19991
Committed 272151@main (2dd5d4cec216): <https://commits.webkit.org/272151@main> Reviewed commits have been landed. Closing PR #19991 and removing active labels.