Increase the stun ping interval.

webrtc/p2p/base/p2ptransportchannel.h

Index: webrtc/p2p/base/p2ptransportchannel.h
diff --git a/webrtc/p2p/base/p2ptransportchannel.h b/webrtc/p2p/base/p2ptransportchannel.h
index ada3ecfb8bb2deeb6bc5d9120eb1647d7cd1a1da..98cf86f760e1a5a70281682235f18eaff246b757 100644
--- a/webrtc/p2p/base/p2ptransportchannel.h
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -40,6 +40,7 @@ namespace cricket {
 
 extern const int WEAK_PING_INTERVAL;
 static const int MIN_PINGS_AT_WEAK_PING_INTERVAL = 3;
+static const int MIN_PINGS_TO_STABILIZE = 10;
 
 struct IceParameters {
   std::string ufrag;
@@ -227,6 +228,7 @@ class P2PTransportChannel : public TransportChannelImpl,
   void RememberRemoteCandidate(const Candidate& remote_candidate,
                                PortInterface* origin_port);
   bool IsPingable(Connection* conn, int64_t now);
+  bool IsBestConnectionPingable();
   void PingConnection(Connection* conn);
   void AddAllocatorSession(std::unique_ptr<PortAllocatorSession> session);
   void AddConnection(Connection* connection);