See: https://github.com/w3c/csswg-drafts/pull/8989
Pull request: https://github.com/WebKit/WebKit/pull/15369
Committed 265617@main (242f3ae3216c): <https://commits.webkit.org/265617@main> Reviewed commits have been landed. Closing PR #15369 and removing active labels.
<rdar://problem/111510558>
Re-opening for pull request https://github.com/WebKit/WebKit/pull/15812
Not sure why this was not auto-closed.