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

Source/core/loader/TextTrackLoader.cpp

 /*
  * Copyright (C) 2011 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 149 matching lines @@
 {
     ASSERT(m_cueParser);
     if (m_cueParser)
         m_cueParser->getNewRegions(outputRegions);
 }
 
 void TextTrackLoader::trace(Visitor* visitor)
 {
     visitor->trace(m_cueParser);
     visitor->trace(m_document);
+    ResourceOwner<RawResource>::trace(visitor);
 }
 
 }