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

webrtc/p2p/base/port.h

Index: webrtc/p2p/base/port.h
diff --git a/webrtc/p2p/base/port.h b/webrtc/p2p/base/port.h
index a36c9f13bdf8af5a8da9a6869242fb3ad4820331..b95d985b21e8a997536a386a5b7364d66ce791a3 100644
--- a/webrtc/p2p/base/port.h
+++ b/webrtc/p2p/base/port.h
@@ -540,6 +540,7 @@ class Connection : public rtc::MessageHandler,
   // transmission. This connection will send STUN ping with USE-CANDIDATE
   // attribute.
   sigslot::signal1<Connection*> SignalUseCandidate;
+
   // Invoked when Connection receives STUN error response with 487 code.
   void HandleRoleConflictFromPeer();
 
@@ -557,6 +558,10 @@ class Connection : public rtc::MessageHandler,
   // |new_candidate|.
   void MaybeUpdatePeerReflexiveCandidate(const Candidate& new_candidate);
 
+  // Returns the last received time of any data, stun request, or stun
+  // response in milliseconds
+  uint32 last_received();
+
  protected:
   enum { MSG_DELETE = 0, MSG_FIRST_AVAILABLE };