Make custom layout actually work.

sky/engine/core/rendering/RenderObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 243 matching lines @@
     void operator delete(void*);
 #endif
 
 public:
     virtual bool isBoxModelObject() const { return false; }
     virtual bool isCanvas() const { return false; }
     virtual bool isImage() const { return false; }
     virtual bool isInlineBlock() const { return false; }
     virtual bool isRenderBlock() const { return false; }
     virtual bool isRenderBlockFlow() const { return false; }
+    virtual bool isRenderCustomLayout() const { return false; }
     virtual bool isRenderParagraph() const { return false; }
     virtual bool isRenderImage() const { return false; }
     virtual bool isRenderInline() const { return false; }
     virtual bool isRenderView() const { return false; }
 
     bool everHadLayout() const { return m_bitfields.everHadLayout(); }
 
     bool alwaysCreateLineBoxesForRenderInline() const
     {
         ASSERT(isRenderInline());
@@ skipping 614 matching lines @@
 void showTree(const blink::RenderObject*);
 void showLineTree(const blink::RenderObject*);
 void showRenderTree(const blink::RenderObject* object1);
 // We don't make object2 an optional parameter so that showRenderTree
 // can be called from gdb easily.
 void showRenderTree(const blink::RenderObject* object1, const blink::RenderObject* object2);
 
 #endif
 
 #endif  // SKY_ENGINE_CORE_RENDERING_RENDEROBJECT_H_