Currently presence of :slotted can easily end up invalidating the whole shadow tree.
<rdar://problem/114480735>
Pull request: https://github.com/WebKit/WebKit/pull/17098
Committed 267326@main (7b40932f6b2a): <https://commits.webkit.org/267326@main> Reviewed commits have been landed. Closing PR #17098 and removing active labels.