videos in in-window mode should have their WebKitPresentationMode property set to inline
<rdar://problem/128482499>
Pull request: https://github.com/WebKit/WebKit/pull/28862
Committed 279143@main (ac7aecf28492): <https://commits.webkit.org/279143@main> Reviewed commits have been landed. Closing PR #28862 and removing active labels.