Introduce DEFINE_AX_OBJECT_TYPE_CASTS to replace manual toFoo() in accessibility child class

Source/core/accessibility/AXTableColumn.h

 /*
  * Copyright (C) 2008 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
@@ skipping 47 matching lines @@
 
 private:
     unsigned m_columnIndex;
     LayoutRect m_columnRect;
 
     virtual bool isTableCol() const OVERRIDE { return true; }
     AXObject* headerObjectForSection(RenderTableSection*, bool thTagRequired);
     virtual bool computeAccessibilityIsIgnored() const OVERRIDE;
 };
 
-inline AXTableColumn* toAXTableColumn(AXObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isTableCol());
-    return static_cast<AXTableColumn*>(object);
-}
-
-inline const AXTableColumn* toAXTableColumn(const AXObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isTableCol());
-    return static_cast<const AXTableColumn*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toAXTableColumn(const AXTableColumn*);
+DEFINE_AX_OBJECT_TYPE_CASTS(AXTableColumn, isTableCol());
 
 } // namespace WebCore
 
 #endif // AXTableColumn_h