Reland "Update rtt on audio only calls".

webrtc/voice_engine/channel_proxy.h

Index: webrtc/voice_engine/channel_proxy.h
diff --git a/webrtc/voice_engine/channel_proxy.h b/webrtc/voice_engine/channel_proxy.h
index 6e0171b39535a47a2e774fbe4c572638521a4a2b..d7a67c4fb06a51649fb153b13fbd0760fad6d818 100644
--- a/webrtc/voice_engine/channel_proxy.h
+++ b/webrtc/voice_engine/channel_proxy.h
@@ -27,6 +27,7 @@ namespace webrtc {
 class AudioSinkInterface;
 class PacketRouter;
 class RtcEventLog;
+class RtcpRttStats;
 class RtpPacketSender;
 class Transport;
 class TransportFeedbackObserver;
@@ -97,6 +98,8 @@ class ChannelProxy {
   virtual void AssociateSendChannel(const ChannelProxy& send_channel_proxy);
   virtual void DisassociateSendChannel();
 
+  virtual void SetRtcpRttStats(RtcpRttStats* rtcp_rtt_stats);
+
  private:
   Channel* channel() const;