We don't hide the system-provided exit fullscreen button when the originating element is a video.
<rdar://problem/103032343>
Pull request: https://github.com/WebKit/WebKit/pull/12399
Committed 262632@main (65b2e06df853): <https://commits.webkit.org/262632@main> Reviewed commits have been landed. Closing PR #12399 and removing active labels.