Hide isXXX() type checking methods in subclasses

Source/core/dom/shadow/InsertionPoint.h

 /*
  * Copyright (C) 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 60 matching lines @@
 
 protected:
     InsertionPoint(const QualifiedName&, Document&);
     virtual bool rendererIsNeeded(const RenderStyle&) OVERRIDE;
     virtual void childrenChanged(const ChildrenChange&) OVERRIDE;
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual void willRecalcStyle(StyleRecalcChange) OVERRIDE;
 
 private:
+    bool isInsertionPoint() const WTF_DELETED_FUNCTION; // Hide to catch useless calls.
+
     ContentDistribution m_distribution;
     bool m_registeredWithShadowRoot;
 };
 
 typedef WillBeHeapVector<RefPtrWillBeMember<InsertionPoint> > DestinationInsertionPoints;
 
 DEFINE_ELEMENT_TYPE_CASTS(InsertionPoint, isInsertionPoint());
 
 inline bool isActiveInsertionPoint(const Node& node)
 {
@@ skipping 19 matching lines @@
     return 0;
 }
 
 const InsertionPoint* resolveReprojection(const Node*);
 
 void collectDestinationInsertionPoints(const Node&, WillBeHeapVector<RawPtrWillBeMember<InsertionPoint>, 8>& results);
 
 } // namespace blink
 
 #endif // InsertionPoint_h