Mark when we may have been invalidated to early out on repaintTreeAfterLayout.

Source/core/rendering/RenderVideo.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 166 matching lines @@
 }
 
 bool RenderVideo::acceleratedRenderingInUse()
 {
     blink::WebLayer* webLayer = mediaElement()->platformLayer();
     return webLayer && !webLayer->isOrphan();
 }
 
 void RenderVideo::layout()
 {
+    setMayNeedInvalidation(true);
     updatePlayer();
     RenderMedia::layout();
 }
 
 HTMLVideoElement* RenderVideo::videoElement() const
 {
     return toHTMLVideoElement(node());
 }
 
 void RenderVideo::updateFromElement()
@@ skipping 85 matching lines @@
             return CompositingReasonVideo;
     }
 
     if ((triggers & VideoTrigger) && shouldDisplayVideo() && supportsAcceleratedRendering())
         return CompositingReasonVideo;
 
     return CompositingReasonNone;
 }
 
 } // namespace WebCore