Reland "Update rtt on audio only calls".

webrtc/voice_engine/channel.h

Index: webrtc/voice_engine/channel.h
diff --git a/webrtc/voice_engine/channel.h b/webrtc/voice_engine/channel.h
index 31c44efccd12cf4038a755e9f096042d26e6cacc..d475475f1838fe2f14ec3edee392776c435445cf 100644
--- a/webrtc/voice_engine/channel.h
+++ b/webrtc/voice_engine/channel.h
@@ -67,6 +67,7 @@ namespace voe {
 
 class OutputMixer;
 class RtcEventLogProxy;
+class RtcpRttStatsProxy;
 class RtpPacketSenderProxy;
 class Statistics;
 class StatisticsProxy;
@@ -412,6 +413,7 @@ class Channel
   // Set a RtcEventLog logging object.
   void SetRtcEventLog(RtcEventLog* event_log);
 
+  void SetRtcpRttStats(RtcpRttStats* rtcp_rtt_stats);
   void SetTransportOverhead(int transport_overhead_per_packet);
 
  protected:
@@ -449,6 +451,7 @@ class Channel
   ChannelState channel_state_;
 
   std::unique_ptr<voe::RtcEventLogProxy> event_log_proxy_;
+  std::unique_ptr<voe::RtcpRttStatsProxy> rtcp_rtt_stats_proxy_;
 
   std::unique_ptr<RtpHeaderParser> rtp_header_parser_;
   std::unique_ptr<RTPPayloadRegistry> rtp_payload_registry_;