Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderIFrame.h

 /*
  * Copyright (C) 2010 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
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 40 matching lines @@
 
     virtual const char* renderName() const OVERRIDE { return "RenderPartObject"; } // Lying for now to avoid breaking tests
 
     virtual bool requiresLayer() const OVERRIDE;
 
     void layoutSeamlessly();
 
     RenderView* contentRootRenderer() const;
 };
 
-inline RenderIFrame* toRenderIFrame(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderIFrame());
-    return static_cast<RenderIFrame*>(object);
-}
-
-inline const RenderIFrame* toRenderIFrame(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderIFrame());
-    return static_cast<const RenderIFrame*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderIFrame(const RenderIFrame*);
-
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderIFrame, isRenderIFrame());
 
 } // namespace WebCore
 
 #endif // RenderIFrame_h