Smaller vtbls in RenderObject

Source/core/rendering/RenderListBox.h

 /*
  * This file is part of the select element renderer in WebCore.
  *
  * Copyright (C) 2006, 2007, 2009 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
@@ skipping 33 matching lines @@
 
     int size() const;
 
     void paintInvalidationOfScrollbarIfNeeded();
 
 private:
     HTMLSelectElement* selectElement() const;
 
     virtual const char* renderName() const OVERRIDE { return "RenderListBox"; }
 
-    virtual bool isListBox() const OVERRIDE { return true; }
+    virtual bool isOfType(RenderObjectType type) const OVERRIDE { return type == RenderObjectListBox || RenderBlockFlow::isOfType(type); }
 
     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const OVERRIDE;
     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const OVERRIDE;
 
     virtual void stopAutoscroll() OVERRIDE;
 
     void setHasVerticalScrollbar(bool hasScrollbar);
     PassRefPtr<Scrollbar> createScrollbar();
     void destroyScrollbar();
 
     LayoutUnit defaultItemHeight() const;
     LayoutUnit itemHeight() const;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderListBox, isListBox());
 
 } // namepace blink
 
 #endif // RenderListBox_h