This makes all the iteration sites check if the frame is a LocalFrame. If it is, behavior is unmodified. If it isn't, it is skipped. We will have to audit the skipping sites one at a time over the coming months and fix all the things, but this is the first step towards getting started.
Pull request: https://github.com/WebKit/WebKit/pull/5478
Committed 255711@main (97a2057f8e50): <https://commits.webkit.org/255711@main> Reviewed commits have been landed. Closing PR #5478 and removing active labels.
<rdar://problem/101320848>