Clean away use of RtpAudioFeedback interface from RTP/RTCP receiver code.

webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h

Index: webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h b/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
index 1dd07d1cc923127f141046183b0ee5069e62c014..b68febbb82b46cdee3d03a9858efa9137d98041d 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
@@ -28,8 +28,7 @@ class CriticalSectionWrapper;
 class RTPReceiverAudio : public RTPReceiverStrategy,
                          public TelephoneEventHandler {
  public:
-  RTPReceiverAudio(RtpData* data_callback,
-                   RtpAudioFeedback* incoming_messages_callback);
+  explicit RTPReceiverAudio(RtpData* data_callback);
   virtual ~RTPReceiverAudio() {}
 
   // The following three methods implement the TelephoneEventHandler interface.
@@ -119,8 +118,6 @@ class RTPReceiverAudio : public RTPReceiverStrategy,
 
   uint8_t num_energy_;
   uint8_t current_remote_energy_[kRtpCsrcSize];
-
-  RtpAudioFeedback* cb_audio_feedback_;
 };
 }  // namespace webrtc