Use continual gathering to restore backup connections

webrtc/p2p/client/basicportallocator.h

Index: webrtc/p2p/client/basicportallocator.h
diff --git a/webrtc/p2p/client/basicportallocator.h b/webrtc/p2p/client/basicportallocator.h
index 8ea66c431e76d560a6299c2831d77a1a83dfeb06..0d27bdd22fdcbc202e6ce637dafe89c0f6ae5dfd 100644
--- a/webrtc/p2p/client/basicportallocator.h
+++ b/webrtc/p2p/client/basicportallocator.h
@@ -47,7 +47,7 @@ class BasicPortAllocator : public PortAllocator {
 
   int network_ignore_mask() const { return network_ignore_mask_; }
 
-  rtc::NetworkManager* network_manager() { return network_manager_; }
+  rtc::NetworkManager* network_manager() const { return network_manager_; }
 
   // If socket_factory() is set to NULL each PortAllocatorSession
   // creates its own socket factory.
@@ -97,6 +97,7 @@ class BasicPortAllocatorSession : public PortAllocatorSession,
   std::vector<PortInterface*> ReadyPorts() const override;
   std::vector<Candidate> ReadyCandidates() const override;
   bool CandidatesAllocationDone() const override;
+  void RegatherOnFailedNetworks() override;
 
  protected:
   void UpdateIceParametersInternal() override;
@@ -170,7 +171,8 @@ class BasicPortAllocatorSession : public PortAllocatorSession,
   void MaybeSignalCandidatesAllocationDone();
   void OnPortAllocationComplete(AllocationSequence* seq);
   PortData* FindPort(Port* port);
-  void GetNetworks(std::vector<rtc::Network*>* networks);
+  std::vector<rtc::Network*> GetNetworks();
+  std::vector<rtc::Network*> GetFailedNetworks();
 
   bool CheckCandidateFilter(const Candidate& c) const;
   bool CandidatePairable(const Candidate& c, const Port* port) const;
@@ -178,6 +180,13 @@ class BasicPortAllocatorSession : public PortAllocatorSession,
   // in order to avoid leaking any information.
   Candidate SanitizeRelatedAddress(const Candidate& c) const;
 
+  // Removes the ports and candidates on given networks.
+  void RemovePortsAndCandidates(const std::vector<rtc::Network*>& networks);
+  // Gets filtered and sanitized candidates generated from a port and
+  // append to |candidates|.
+  void GetCandidatesFromPort(const PortData& data,
+                             std::vector<Candidate>* candidates) const;
+
   BasicPortAllocator* allocator_;
   rtc::Thread* network_thread_;
   std::unique_ptr<rtc::PacketSocketFactory> owned_socket_factory_;
@@ -255,11 +264,13 @@ class AllocationSequence : public rtc::MessageHandler,
   ~AllocationSequence();
   bool Init();
   void Clear();
-  void OnNetworkRemoved();
+  void OnNetworkFailed();
 
   State state() const { return state_; }
-  const rtc::Network* network() const { return network_; }
-  bool network_removed() const { return network_removed_; }
+  rtc::Network* network() const { return network_; }
+
+  bool network_failed() const { return network_failed_; }
+  void set_network_failed() { network_failed_ = true; }
 
   // Disables the phases for a new sequence that this one already covers for an
   // equivalent network setup.
@@ -309,7 +320,7 @@ class AllocationSequence : public rtc::MessageHandler,
   void OnPortDestroyed(PortInterface* port);
 
   BasicPortAllocatorSession* session_;
-  bool network_removed_ = false;
+  bool network_failed_ = false;
   rtc::Network* network_;
   rtc::IPAddress ip_;
   PortConfiguration* config_;