Add a continual_gathering_policy in PeerConnection RTCConfiguration

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 51426239db1b46f9260e6a52a35cff682e3c5648..2e6aae05c23ac9fa14cf3afc5be0a5fd13ec4e1d 100644
--- a/webrtc/p2p/base/p2ptransportchannel.h
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -74,9 +74,9 @@ class P2PTransportChannel : public TransportChannelImpl,
     return gathering_state_;
   }
   void AddRemoteCandidate(const Candidate& candidate) override;
-  // Sets the receiving timeout in milliseconds.
+  // Sets the receiving timeout and continuous_gathering.
   // This also sets the check_receiving_delay proportionally.
-  void SetReceivingTimeout(int receiving_timeout_ms) override;
+  void SetIceConfig(const IceConfig& config) override;
 
   // From TransportChannel:
   int SendPacket(const char* data,
@@ -250,6 +250,7 @@ class P2PTransportChannel : public TransportChannelImpl,
   int check_receiving_delay_;
   int receiving_timeout_;
   uint32 last_ping_sent_ms_ = 0;
+  bool continuous_gathering_ = false;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(P2PTransportChannel);
 };