:open / :closed pseudo-classes
*** Bug 252216 has been marked as a duplicate of this bug. ***
<rdar://problem/105435152>
Pull request: https://github.com/WebKit/WebKit/pull/10074
Committed 260267@main (b206da85c2b3): <https://commits.webkit.org/260267@main> Reviewed commits have been landed. Closing PR #10074 and removing active labels.