Add flakiness check if there is no received packets in a certain period.

talk/app/webrtc/peerconnection.h

Index: talk/app/webrtc/peerconnection.h
diff --git a/talk/app/webrtc/peerconnection.h b/talk/app/webrtc/peerconnection.h
index bea9c2f61b610c83129c01f76af2f8f1080b57d2..1f6b59f832e96b335a3baae8ff780bdd61b5352c 100644
--- a/talk/app/webrtc/peerconnection.h
+++ b/talk/app/webrtc/peerconnection.h
@@ -142,13 +142,14 @@ class PeerConnection : public PeerConnectionInterface,
                                uint32 ssrc) override;
   void OnRemoveLocalVideoTrack(MediaStreamInterface* stream,
                                VideoTrackInterface* video_track) override;
-  virtual void OnRemoveLocalStream(MediaStreamInterface* stream);
+  void OnRemoveLocalStream(MediaStreamInterface* stream) override;
 
   // Implements IceObserver
-  virtual void OnIceConnectionChange(IceConnectionState new_state);
-  virtual void OnIceGatheringChange(IceGatheringState new_state);
-  virtual void OnIceCandidate(const IceCandidateInterface* candidate);
-  virtual void OnIceComplete();
+  void OnIceConnectionChange(IceConnectionState new_state) override;
+  void OnIceGatheringChange(IceGatheringState new_state) override;
+  void OnIceCandidate(const IceCandidateInterface* candidate) override;
+  void OnIceComplete() override;
+  void OnIceConnectionReceivingChange(bool receiving) override;
 
   // Signals from WebRtcSession.
   void OnSessionStateChange(cricket::BaseSession* session,