Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderButton.h

 /*
  * Copyright (C) 2005 Apple Computer
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 50 matching lines @@
     virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle);
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
 
     virtual bool hasLineIfEmpty() const { return node() && node()->hasTagName(HTMLNames::inputTag); }
 
     virtual bool requiresForcedStyleRecalcPropagation() const { return true; }
 
     RenderBlock* m_inner;
 };
 
-inline RenderButton* toRenderButton(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderButton());
-    return static_cast<RenderButton*>(object);
-}
-
-inline const RenderButton* toRenderButton(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderButton());
-    return static_cast<const RenderButton*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderButton(const RenderButton*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderButton, isRenderButton());
 
 } // namespace WebCore
 
 #endif // RenderButton_h