Reloading http://trac.webkit.org/export/153570/trunk/LayoutTests/compositing/overflow/overflow-compositing-descendant.html on mountain lion shows a flash of garbage pixels where the video should be.
RenderVideo::foregroundIsKnownToBeOpaqueInRect() lies. It needs to ask the media player if it's actually going to show anything.
Created attachment 209318 [details] Patch
Comment on attachment 209318 [details] Patch Attachment 209318 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/1393100 New failing tests: fast/workers/termination-with-port-messages.html
Created attachment 209341 [details] Archive of layout-test-results from webkit-ews-10 for mac-mountainlion-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: webkit-ews-10 Port: mac-mountainlion-wk2 Platform: Mac OS X 10.8.4
Comment on attachment 209318 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=209318&action=review > Source/WebCore/rendering/RenderVideo.cpp:350 > + MediaPlayer* player = mediaElement()->player(); > + if (player) I'd put these on the same line.
https://trac.webkit.org/r154455