Fix an issue that subtitle is not shown for native fullscreen video that is inside an iframe

Source/core/rendering/compositing/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 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 296 matching lines @@
     const FrameView::ScrollableAreaSet* scrollableAreas = m_renderView->frameView()->scrollableAreas();
     if (!scrollableAreas)
         return;
 
     for (FrameView::ScrollableAreaSet::iterator it = scrollableAreas->begin(); it != scrollableAreas->end(); ++it)
         (*it)->updateNeedsCompositedScrolling();
 }
 
 static RenderVideo* findFullscreenVideoRenderer(Document& document)
 {
-    Element* fullscreenElement = FullscreenElementStack::currentFullScreenElementFrom(document);
+    Element* fullscreenElement = FullscreenElementStack::fullscreenElementFrom(document);
     while (fullscreenElement && fullscreenElement->isFrameOwnerElement()) {
         Document* contentDocument = toHTMLFrameOwnerElement(fullscreenElement)->contentDocument();
         if (!contentDocument)
             return 0;
-        fullscreenElement = FullscreenElementStack::currentFullScreenElementFrom(*contentDocument);
+        fullscreenElement = FullscreenElementStack::fullscreenElementFrom(*contentDocument);
     }
     if (!fullscreenElement || !fullscreenElement->hasTagName(videoTag))
         return 0;
     RenderObject* renderer = fullscreenElement->renderer();
     if (!renderer)
         return 0;
     return toRenderVideo(renderer);
 }
 
 void RenderLayerCompositor::finishCompositingUpdateForFrameTree(LocalFrame* frame)
@@ skipping 1898 matching lines @@
     } else if (graphicsLayer == m_scrollLayer.get()) {
         name = "LocalFrame Scrolling Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore