Reland "Update rtt on audio only calls".

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 1d67f689a7ac41160130715f79e08ae237a12e59..8b140a5724af5a8038b0aa2ceef0775486636462 100644
--- a/webrtc/voice_engine/channel_proxy.cc
+++ b/webrtc/voice_engine/channel_proxy.cc
@@ -249,6 +249,11 @@ void ChannelProxy::DisassociateSendChannel() {
   channel()->set_associate_send_channel(ChannelOwner(nullptr));
 }
 
+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();