bug 1210266 unfriend AudioBufferSourceNode from AudioNode r=padenot

--HG--
extra : rebase_source : 8476dc3499835906378c910f879be7a2652fea81

dom/media/webaudio/AudioNode.h

@@ -211,7 +211,6 @@ public:
   virtual const char* NodeType() const = 0;
 
 private:
-  friend class AudioBufferSourceNode;
   // This could possibly delete 'this'.
   void DisconnectFromGraph();