REGRESSION (r171197): Clip's content is drawn behind Safari window when entering Full Screen youtube html5 first time
<rdar://problem/18325063>
Created attachment 238546 [details] Patch
Created attachment 238563 [details] Patch
Comment on attachment 238563 [details] Patch r=me.
Committed r173888: <http://trac.webkit.org/changeset/173888>