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

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1555 matching lines @@
         if ((forceCheckOfNextElementSibling || forceCheckOfAnyElementSibling))
             element->setNeedsStyleRecalc();
         if (shouldRecalcStyle(change, element)) {
             parentPusher.push();
             element->recalcStyle(change);
         }
         forceCheckOfNextElementSibling = childRulesChanged && hasDirectAdjacentRules;
         forceCheckOfAnyElementSibling = forceCheckOfAnyElementSibling || (childRulesChanged && hasIndirectAdjacentRules);
     }
 
-    if (shouldRecalcStyle(change, this))
+    if (shouldRecalcStyle(change, this)) {
         updatePseudoElement(AFTER, change);
+        updatePseudoElement(BACKDROP, change);
+    }
 
     clearNeedsStyleRecalc();
     clearChildNeedsStyleRecalc();
 
     if (hasCustomStyleCallbacks())
         didRecalcStyle(change);
 }
 
 ElementShadow* Element::shadow() const
 {
@@ skipping 2059 matching lines @@
     return 0;
 }
 
 Attribute* UniqueElementData::attributeItem(unsigned index)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(index < length());
     return &m_attributeVector.at(index);
 }
 
 } // namespace WebCore