Revert of Add RtcpRttStats to AudioStream

webrtc/voice_engine/channel_proxy.cc

Index: webrtc/voice_engine/channel_proxy.cc
diff --git a/webrtc/voice_engine/channel_proxy.cc b/webrtc/voice_engine/channel_proxy.cc
index b7cfa9fd01e94fabf294133d7e4e5bfdce848473..fc22180566ccba2948cfa9e093ed58dcc6fcb185 100644
--- a/webrtc/voice_engine/channel_proxy.cc
+++ b/webrtc/voice_engine/channel_proxy.cc
@@ -214,11 +214,6 @@
   channel()->SetRtcEventLog(event_log);
 }
 
-void ChannelProxy::SetRtcpRttStats(RtcpRttStats* rtcp_rtt_stats) {
-  RTC_DCHECK(thread_checker_.CalledOnValidThread());
-  channel()->SetRtcpRttStats(rtcp_rtt_stats);
-}
-
 Channel* ChannelProxy::channel() const {
   RTC_DCHECK(channel_owner_.channel());
   return channel_owner_.channel();