Rename DOMWindow to LocalDOMWindow, as we are moving towards site isolation.
Pull request: https://github.com/WebKit/WebKit/pull/11498
Committed 261652@main (2b723a047e7e): <https://commits.webkit.org/261652@main> Reviewed commits have been landed. Closing PR #11498 and removing active labels.
<rdar://problem/106724069>