Add Stats to Stun ping.

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 7ec33bcd0b18169f22998026ee4bd19d37be8830..3ed3611f206a2eaf116e3ecbe313371fbbe86cf9 100644
--- a/webrtc/p2p/base/port.h
+++ b/webrtc/p2p/base/port.h
@@ -477,8 +477,10 @@ class Connection : public CandidatePairInterface,
   // to errors.
   size_t sent_discarded_packets();
   size_t sent_total_packets();
+  size_t sent_ping_requests();
   size_t recv_total_bytes();
   size_t recv_bytes_second();
+  size_t recv_ping_responses();
   sigslot::signal1<Connection*> SignalStateChange;
 
   // Sent when the connection has decided that it is no longer of value.  It
@@ -647,6 +649,8 @@ class Connection : public CandidatePairInterface,
   rtc::RateTracker send_rate_tracker_;
   uint32_t sent_packets_discarded_;
   uint32_t sent_packets_total_;
+  uint32_t sent_ping_requests_;
+  uint32_t recv_ping_responses_;
 
  private:
   void MaybeAddPrflxCandidate(ConnectionRequest* request,