Adding "first packet received" notification to PeerConnectionObserver.

talk/app/webrtc/peerconnection_unittest.cc

Index: talk/app/webrtc/peerconnection_unittest.cc
diff --git a/talk/app/webrtc/peerconnection_unittest.cc b/talk/app/webrtc/peerconnection_unittest.cc
index 8d0793e25f83f90e85f848e7277725490c707824..ef3bf6288c3cc0b3210b20f6dd6131a5208d7b01 100644
--- a/talk/app/webrtc/peerconnection_unittest.cc
+++ b/talk/app/webrtc/peerconnection_unittest.cc
@@ -251,6 +251,7 @@ class PeerConnectionTestClient : public webrtc::PeerConnectionObserver,
     signaling_message_receiver_->ReceiveIceMessage(
         candidate->sdp_mid(), candidate->sdp_mline_index(), ice_sdp);
   }
+  void OnFirstPacketReceived() override { received_packet_ = true; }
 
   // MediaStreamInterface callback
   void OnChanged() override {
@@ -386,6 +387,8 @@ class PeerConnectionTestClient : public webrtc::PeerConnectionObserver,
     return true;
   }
 
+  bool received_packet() const { return received_packet_; }
+
   void OnIceComplete() override { LOG(INFO) << id_ << "OnIceComplete"; }
 
   void OnDataChannel(DataChannelInterface* data_channel) override {
@@ -924,6 +927,10 @@ class PeerConnectionTestClient : public webrtc::PeerConnectionObserver,
 
   rtc::scoped_refptr<DataChannelInterface> data_channel_;
   rtc::scoped_ptr<MockDataChannelObserver> data_observer_;
+
+  // "true" if the PeerConnection indicated that a packet was received,
+  // through PeerConnectionObserverInterface.
+  bool received_packet_ = false;
 };
 
 class P2PTestConductor : public testing::Test {
@@ -1104,6 +1111,10 @@ class P2PTestConductor : public testing::Test {
 
     EXPECT_TRUE_WAIT(FramesNotPending(audio_frame_count, video_frame_count),
                      kMaxWaitForFramesMs);
+    if (audio_frame_count != -1 || video_frame_count != -1) {
+      EXPECT_TRUE(initiating_client_->received_packet());
+      EXPECT_TRUE(receiving_client_->received_packet());
+    }
   }
 
   void SetupAndVerifyDtlsCall() {