See https://github.com/whatwg/html/issues/3950 Test https://github.com/web-platform-tests/wpt/pull/12801
<rdar://problem/44118431>
Committed 258074@main (05f693e31a84): <https://commits.webkit.org/258074@main> Reviewed commits have been landed. Closing PR #7830 and removing active labels.