Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 702 matching lines @@
     InlineBox* m_inlineBoxWrapper;
 
     // Our overflow information.
     OwnPtr<RenderOverflow> m_overflow;
 
 private:
     // Used to store state between styleWillChange and styleDidChange
     static bool s_hadOverflowClip;
 };
 
-inline RenderBox* toRenderBox(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isBox());
-    return static_cast<RenderBox*>(object);
-}
-
-inline const RenderBox* toRenderBox(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isBox());
-    return static_cast<const RenderBox*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderBox(const RenderBox*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBox, isBox());
 
 inline RenderBox* RenderBox::previousSiblingBox() const
 {
     return toRenderBox(previousSibling());
 }
 
 inline RenderBox* RenderBox::nextSiblingBox() const
 {
     return toRenderBox(nextSibling());
 }
@@ skipping 24 matching lines @@
         if (UNLIKELY(m_inlineBoxWrapper != 0))
             deleteLineBoxWrapper();
     }
 
     m_inlineBoxWrapper = boxWrapper;
 }
 
 } // namespace WebCore
 
 #endif // RenderBox_h