https://www.w3.org/TR/css-highlight-api-1/#priorities
<rdar://problem/111866042>
Pull request: https://github.com/WebKit/WebKit/pull/15765
Pull request: https://github.com/WebKit/WebKit/pull/15858
Committed 266117@main (ec22e0752450): <https://commits.webkit.org/266117@main> Reviewed commits have been landed. Closing PR #15858 and removing active labels.