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

talk/app/webrtc/peerconnectioninterface.h

Index: talk/app/webrtc/peerconnectioninterface.h
diff --git a/talk/app/webrtc/peerconnectioninterface.h b/talk/app/webrtc/peerconnectioninterface.h
index 3e4cb556fb5f51826734c719a5cf3f6e46bc36e8..6e238096ffe3843b5ae8727f6a90bb77840badf4 100644
--- a/talk/app/webrtc/peerconnectioninterface.h
+++ b/talk/app/webrtc/peerconnectioninterface.h
@@ -408,6 +408,9 @@ class PeerConnectionObserver {
   // All Ice candidates have been found.
   virtual void OnIceComplete() {}
 
+  // Called when the ICE transport flakiness changes.
+  virtual void OnIceFlakinessChange(bool flaky) {}
+
  protected:
   // Dtor protected as objects shouldn't be deleted via this interface.
   ~PeerConnectionObserver() {}