am 712a8cca: Merge "VolumePreference.onActivityStop only stops playback"

* commit '712a8cca1f9e438af224f93c3a4644853331af2e':
  VolumePreference.onActivityStop only stops playback
diff --git a/include/utils/RefBase.h b/include/utils/RefBase.h
index 0af7e6a..d92cfb0 100644
--- a/include/utils/RefBase.h
+++ b/include/utils/RefBase.h
@@ -115,7 +115,6 @@
     // used to override the RefBase destruction.
     class Destroyer {
         friend class RefBase;
-        friend class weakref_type;
     public:
         virtual ~Destroyer();
     private: