Keep on sending stun binding requests on zero-cost networks.

webrtc/p2p/base/stunport.h

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 88 matching lines @@
     return protocol == UDP_PROTOCOL_NAME;
   }
 
   void set_stun_keepalive_delay(int delay) {
     stun_keepalive_delay_ = delay;
   }
   int stun_keepalive_delay() const {
     return stun_keepalive_delay_;
   }
 
+  // Visible for testing.
+  int stun_keepalive_lifetime() const { return stun_keepalive_lifetime_; }
+  void set_stun_keepalive_lifetime(int lifetime) {
+    stun_keepalive_lifetime_ = lifetime;
+  }
+  // Returns true if there is a pending request with type |msg_type|.
+  bool RequestExists(int msg_type) { return requests_.Exist(msg_type); }

[pthatcher1, 2016/03/02 20:25:59]

A better name might be HasPendingRequest

[honghaiz3, 2016/03/02 23:22:51]

Done.

+
  protected:
   UDPPort(rtc::Thread* thread,
           rtc::PacketSocketFactory* factory,
           rtc::Network* network,
           const rtc::IPAddress& ip,
           uint16_t min_port,
           uint16_t max_port,
           const std::string& username,
           const std::string& password,
           const std::string& origin,
@@ skipping 91 matching lines @@
 
   ServerAddresses server_addresses_;
   ServerAddresses bind_request_succeeded_servers_;
   ServerAddresses bind_request_failed_servers_;
   StunRequestManager requests_;
   rtc::AsyncPacketSocket* socket_;
   int error_;
   rtc::scoped_ptr<AddressResolver> resolver_;
   bool ready_;
   int stun_keepalive_delay_;
+  int stun_keepalive_lifetime_;
 
   // This is true by default and false when
   // PORTALLOCATOR_DISABLE_DEFAULT_LOCAL_CANDIDATE is specified.
   bool emit_local_for_anyaddress_;
 
   friend class StunBindingRequest;
 };
 
 class StunPort : public UDPPort {
  public:
@@ skipping 47 matching lines @@
                 false) {
     // UDPPort will set these to local udp, updating these to STUN.
     set_type(STUN_PORT_TYPE);
     set_server_addresses(servers);
   }
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_STUNPORT_H_