Sometimes, layer.contentsDirtyRect is not the null rect when we expect it to be.
<rdar://111229068>
Pull request: https://github.com/WebKit/WebKit/pull/15390
Committed 265631@main (72ba23e6beb5): <https://commits.webkit.org/265631@main> Reviewed commits have been landed. Closing PR #15390 and removing active labels.