Make it possible to keep the port allocator session running

webrtc/p2p/base/portallocator.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 73 matching lines @@
   virtual ~PortAllocatorSession() {}
 
   uint32 flags() const { return flags_; }
   void set_flags(uint32 flags) { flags_ = flags; }
   std::string content_name() const { return content_name_; }
   int component() const { return component_; }
 
   // Starts gathering STUN and Relay configurations.
   virtual void StartGettingPorts() = 0;
   virtual void StopGettingPorts() = 0;
+  // Only stop the existing gathering process but may start new ones if needed.
+  virtual void ClearGettingPorts() = 0;
+  // Whether the process of getting ports has been stopped.
   virtual bool IsGettingPorts() = 0;
 
   sigslot::signal2<PortAllocatorSession*, PortInterface*> SignalPortReady;
   sigslot::signal2<PortAllocatorSession*,
                    const std::vector<Candidate>&> SignalCandidatesReady;
   sigslot::signal1<PortAllocatorSession*> SignalCandidatesAllocationDone;
 
   virtual uint32 generation() { return generation_; }
   virtual void set_generation(uint32 generation) { generation_ = generation; }
   sigslot::signal1<PortAllocatorSession*> SignalDestroyed;
@@ skipping 95 matching lines @@
   int max_port_;
   uint32 step_delay_;
   bool allow_tcp_listen_;
   uint32 candidate_filter_;
   std::string origin_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_PORTALLOCATOR_H_