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

Source/core/dom/PendingScript.cpp

 /*
  * 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 37 matching lines @@
     setResource(resource);
 }
 
 void PendingScript::notifyFinished(Resource*)
 {
 }
 
 void PendingScript::trace(Visitor* visitor)
 {
     visitor->trace(m_element);
+    ResourceOwner<ScriptResource>::trace(visitor);
 }
 
 }