[WIP] Migrate Fullscreen to use top layer instead of RenderFullScreen

Source/core/html/HTMLMediaElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 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 478 matching lines @@
 
 RenderObject* HTMLMediaElement::createRenderer(RenderStyle*)
 {
     return new (document()->renderArena()) RenderMedia(this);
 }
 
 bool HTMLMediaElement::childShouldCreateRenderer(const NodeRenderingContext& childContext) const
 {
     if (!hasMediaControls())
         return false;
+
     // <media> doesn't allow its content, including shadow subtree, to
     // be rendered. So this should return false for most of the children.
     // One exception is a shadow tree built for rendering controls which should be visible.
     // So we let them go here by comparing its subtree root with one of the controls.
-    return (mediaControls()->treeScope() == childContext.node()->treeScope()
-            && childContext.isOnUpperEncapsulationBoundary() && HTMLElement::childShouldCreateRenderer(childContext));
+    if ((mediaControls()->treeScope() == childContext.node()->treeScope()
+        && childContext.isOnUpperEncapsulationBoundary() && HTMLElement::childShouldCreateRenderer(childContext)))
+        return true;
+    if (childContext.node()->pseudoId() == BACKDROP)
+        return true;
+
+    return false;
 }
 
 Node::InsertionNotificationRequest HTMLMediaElement::insertedInto(ContainerNode* insertionPoint)
 {
     LOG(Media, "HTMLMediaElement::insertedInto");
 
     HTMLElement::insertedInto(insertionPoint);
     if (insertionPoint->inDocument()) {
         m_inActiveDocument = true;
 
@@ skipping 3458 matching lines @@
     info.addMember(m_mediaGroup, "mediaGroup");
     info.addMember(m_mediaController, "mediaController");
 
 #if ENABLE(WEB_AUDIO)
     info.addMember(m_audioSourceNode, "audioSourceNode");
 #endif
 
 }
 
 }