Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderRegion.h

 /*
  * Copyright (C) 2011 Adobe Systems Incorporated. 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.
@@ skipping 198 matching lines @@
     typedef HashMap<const RenderObject*, ObjectRegionStyleInfo > RenderObjectRegionStyleMap;
     RenderObjectRegionStyleMap m_renderObjectRegionStyle;
 
     LayoutUnit m_computedAutoHeight;
 
     bool m_isValid : 1;
     bool m_hasCustomRegionStyle : 1;
     bool m_hasAutoLogicalHeight : 1;
 };
 
-inline RenderRegion* toRenderRegion(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderRegion());
-    return static_cast<RenderRegion*>(object);
-}
-
-inline const RenderRegion* toRenderRegion(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderRegion());
-    return static_cast<const RenderRegion*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderRegion(const RenderRegion*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderRegion, isRenderRegion());
 
 } // namespace WebCore
 
 #endif // RenderRegion_h