RefCounted types should not have public destructors, delegate cleanup

media/audio/audio_output_controller.h

Index: media/audio/audio_output_controller.h
diff --git a/media/audio/audio_output_controller.h b/media/audio/audio_output_controller.h
index 2077c9bb2dadb60c47f13affae2a282f2a4317c0..8a68d36cf6ea48354b1329774fbb06cb7962bf1d 100644
--- a/media/audio/audio_output_controller.h
+++ b/media/audio/audio_output_controller.h
@@ -76,11 +76,13 @@ class MEDIA_EXPORT AudioOutputController
   // following methods are called on the audio manager thread.
   class MEDIA_EXPORT EventHandler {
    public:
-    virtual ~EventHandler() {}
     virtual void OnCreated(AudioOutputController* controller) = 0;
     virtual void OnPlaying(AudioOutputController* controller) = 0;
     virtual void OnPaused(AudioOutputController* controller) = 0;
     virtual void OnError(AudioOutputController* controller, int error_code) = 0;
+
+   protected:
+    virtual ~EventHandler() {}
   };
 
   // A synchronous reader interface used by AudioOutputController for