Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderListMarker.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009 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 68 matching lines @@
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
 
     IntRect getRelativeMarkerRect();
     LayoutRect localSelectionRect();
 
     String m_text;
     RefPtr<StyleImage> m_image;
     RenderListItem* m_listItem;
 };
 
-inline RenderListMarker* toRenderListMarker(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isListMarker());
-    return static_cast<RenderListMarker*>(object);
-}
-
-inline const RenderListMarker* toRenderListMarker(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isListMarker());
-    return static_cast<const RenderListMarker*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderListMarker(const RenderListMarker*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderListMarker, isListMarker());
 
 } // namespace WebCore
 
 #endif // RenderListMarker_h