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

Source/core/accessibility/AXTableColumn.h

Index: Source/core/accessibility/AXTableColumn.h
diff --git a/Source/core/accessibility/AXTableColumn.h b/Source/core/accessibility/AXTableColumn.h
index 8061b1d310b8e42930c7efa3d44602e7c1e55b0e..9da318774da2c36ae9d0a0081cbf680f8fe4fdab 100644
--- a/Source/core/accessibility/AXTableColumn.h
+++ b/Source/core/accessibility/AXTableColumn.h
@@ -65,20 +65,7 @@ private:
     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