Move the refcounting from the proxy/impl resource object to the shared resource object base class.

ppapi/shared_impl/audio_impl.h

Index: ppapi/shared_impl/audio_impl.h
diff --git a/ppapi/shared_impl/audio_impl.h b/ppapi/shared_impl/audio_impl.h
index 4916cd6a1aa5d8c902873862736bd8a9625d377b..a640d37328e94ee56610c9dd92cf5588fc1e82f9 100644
--- a/ppapi/shared_impl/audio_impl.h
+++ b/ppapi/shared_impl/audio_impl.h
@@ -18,16 +18,12 @@ namespace ppapi {
 // Implements the logic to map shared memory and run the audio thread signaled
 // from the sync socket. Both the proxy and the renderer implementation use
 // this code.
-class AudioImpl : public ResourceObjectBase,
-                  public thunk::PPB_Audio_API,
+class AudioImpl : public thunk::PPB_Audio_API,
                   public base::DelegateSimpleThread::Delegate {
  public:
   AudioImpl();
   virtual ~AudioImpl();
 
-  // ResourceObjectBase implementation.
-  virtual ::ppapi::thunk::PPB_Audio_API* AsPPB_Audio_API() OVERRIDE;
-
   bool playing() const { return playing_; }
 
   // Sets the callback information that the background thread will use. This