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

talk/app/webrtc/peerconnection.cc

Index: talk/app/webrtc/peerconnection.cc
diff --git a/talk/app/webrtc/peerconnection.cc b/talk/app/webrtc/peerconnection.cc
index 4c54d6f5feb62c2b4f1b5f25da091ac30d8e4439..487b975ce331cc02dcef877388a9535a9905761e 100644
--- a/talk/app/webrtc/peerconnection.cc
+++ b/talk/app/webrtc/peerconnection.cc
@@ -886,6 +886,11 @@ void PeerConnection::OnIceComplete() {
   observer_->OnIceComplete();
 }
 
+void PeerConnection::OnIceConnectionReceivingChange(bool receiving) {
+  ASSERT(signaling_thread()->IsCurrent());
+  observer_->OnIceConnectionReceivingChange(receiving);
+}
+
 void PeerConnection::ChangeSignalingState(
     PeerConnectionInterface::SignalingState signaling_state) {
   signaling_state_ = signaling_state;