Refactor RenderTreeBuilder and expose special <dialog>

Source/core/html/HTMLDialogElement.h

 /*
  * Copyright (C) 2012 Google 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
@@ skipping 44 matching lines @@
     void setNotCentered();
 
     String returnValue() const { return m_returnValue; }
     void setReturnValue(const String& returnValue) { m_returnValue = returnValue; }
 
 private:
     explicit HTMLDialogElement(Document&);
 
     virtual bool isPresentationAttribute(const QualifiedName&) const OVERRIDE;
     virtual void defaultEventHandler(Event*) OVERRIDE;
-    virtual bool shouldBeReparentedUnderRenderView(const RenderStyle*) const OVERRIDE;
 
     void forceLayoutForCentering();
 
     CenteringMode m_centeringMode;
     LayoutUnit m_centeredPosition;
     String m_returnValue;
 };
 
 inline bool isHTMLDialogElement(const Node& node)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(RuntimeEnabledFeatures::dialogElementEnabled());
     return node.hasTagName(HTMLNames::dialogTag);
 }
 
 DEFINE_NODE_TYPE_CASTS_WITH_FUNCTION(HTMLDialogElement);
 
 } // namespace WebCore
 
 #endif