Adding "first packet received" notification to PeerConnectionObserver.

talk/app/webrtc/webrtcsession.cc

Index: talk/app/webrtc/webrtcsession.cc
diff --git a/talk/app/webrtc/webrtcsession.cc b/talk/app/webrtc/webrtcsession.cc
index 41e22daac2c555b3e060998f5120599890ac1e19..c092cb8e3e62e14070d810e84969a24fbcd0efea 100644
--- a/talk/app/webrtc/webrtcsession.cc
+++ b/talk/app/webrtc/webrtcsession.cc
@@ -1844,6 +1844,8 @@ bool WebRtcSession::CreateVoiceChannel(const cricket::ContentInfo* content) {
 
   voice_channel_->SignalDtlsSetupFailure.connect(
       this, &WebRtcSession::OnDtlsSetupFailure);
+  voice_channel_->SignalFirstPacketReceived.connect(
+      this, &WebRtcSession::OnChannelFirstPacketReceived);
 
   SignalVoiceChannelCreated();
   voice_channel_->transport_channel()->SignalSentPacket.connect(
@@ -1861,6 +1863,8 @@ bool WebRtcSession::CreateVideoChannel(const cricket::ContentInfo* content) {
 
   video_channel_->SignalDtlsSetupFailure.connect(
       this, &WebRtcSession::OnDtlsSetupFailure);
+  video_channel_->SignalFirstPacketReceived.connect(
+      this, &WebRtcSession::OnChannelFirstPacketReceived);
 
   SignalVideoChannelCreated();
   video_channel_->transport_channel()->SignalSentPacket.connect(
@@ -1883,6 +1887,8 @@ bool WebRtcSession::CreateDataChannel(const cricket::ContentInfo* content) {
 
   data_channel_->SignalDtlsSetupFailure.connect(
       this, &WebRtcSession::OnDtlsSetupFailure);
+  data_channel_->SignalFirstPacketReceived.connect(
+      this, &WebRtcSession::OnChannelFirstPacketReceived);
 
   SignalDataChannelCreated();
   data_channel_->transport_channel()->SignalSentPacket.connect(
@@ -1895,6 +1901,14 @@ void WebRtcSession::OnDtlsSetupFailure(cricket::BaseChannel*, bool rtcp) {
            rtcp ? kDtlsSetupFailureRtcp : kDtlsSetupFailureRtp);
 }
 
+void WebRtcSession::OnChannelFirstPacketReceived(cricket::BaseChannel*) {
+  ASSERT(signaling_thread()->IsCurrent());
+  if (has_received_packet_) {

[pthatcher1, 2016/01/14 23:50:09]

Should that be "!has_recieved_packet_"?

[Taylor Brandstetter, 2016/01/15 17:06:58]

Yep; I would have noticed this pretty quickly if I remembered to run the unit
tests...

+    has_received_packet_ = true;
+    SignalFirstPacketReceived();
+  }
+}
+
 void WebRtcSession::OnDataChannelMessageReceived(
     cricket::DataChannel* channel,
     const cricket::ReceiveDataParams& params,