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

Source/core/fetch/ResourceLoader.h

 /*
  * Copyright (C) 2005, 2006, 2011 Apple 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
@@ skipping 34 matching lines @@
 class Resource;
 class KURL;
 class ResourceError;
 class ResourceResponse;
 class ResourceLoaderHost;
 
 class ResourceLoader FINAL : public RefCountedWillBeGarbageCollectedFinalized<ResourceLoader>, protected WebURLLoaderClient {
 public:
     static PassRefPtrWillBeRawPtr<ResourceLoader> create(ResourceLoaderHost*, Resource*, const ResourceRequest&, const ResourceLoaderOptions&);
     virtual ~ResourceLoader();
-    void trace(Visitor*);
+    virtual void trace(Visitor*);
 
     void start();
     void changeToSynchronous();
 
     void cancel();
     void cancel(const ResourceError&);
     void cancelIfNotFinishing();
 
     Resource* cachedResource() { return m_resource; }
     const ResourceRequest& originalRequest() const { return m_originalRequest; }
@@ skipping 80 matching lines @@
     // Used for sanity checking to make sure we don't experience illegal state
     // transitions.
     ConnectionState m_connectionState;
 
     OwnPtr<RequestCountTracker> m_requestCountTracker;
 };
 
 }
 
 #endif