Oilpan: Ensure that classes with virtual trace methods always have vtables for their left-most base…

Source/core/dom/PendingScript.h

 /*
  * Copyright (C) 2010 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:
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 80 matching lines @@
     void setWatchingForLoad(bool b) { m_watchingForLoad = b; }
 
     Element* element() const { return m_element.get(); }
     void setElement(Element* element) { m_element = element; }
     PassRefPtrWillBeRawPtr<Element> releaseElementAndClear();
 
     void setScriptResource(ScriptResource*);
 
     virtual void notifyFinished(Resource*);
 
-    void trace(Visitor*);
+    virtual void trace(Visitor*) OVERRIDE;
 
 private:
     bool m_watchingForLoad;
     RefPtrWillBeMember<Element> m_element;
     TextPosition m_startingPosition; // Only used for inline script tags.
 };
 
 }
 
 #endif