Early connection migration in QUIC.

net/quic/quic_stream_factory.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_QUIC_QUIC_STREAM_FACTORY_H_
 #define NET_QUIC_QUIC_STREAM_FACTORY_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 134 matching lines @@
       int max_recent_disabled_reasons,
       int threshold_timeouts_with_streams_open,
       int threshold_public_resets_post_handshake,
       int socket_receive_buffer_size,
       bool delay_tcp_race,
       int max_server_configs_stored_in_properties,
       bool close_sessions_on_ip_change,
       bool disable_quic_on_timeout_with_open_streams,
       int idle_connection_timeout_seconds,
       bool migrate_sessions_on_network_change,
+      bool migrate_sessions_early,
       const QuicTagVector& connection_options);
   ~QuicStreamFactory() override;
 
   // Returns true if there is an existing session to |server_id| which can be
   // used for request to |origin_host|.
   bool CanUseExistingSession(QuicServerId server_id,
                              PrivacyMode privacy_mode,
                              StringPiece origin_host);
 
   // Creates a new QuicHttpStream to |host_port_pair| which will be
@@ skipping 330 matching lines @@
   int yield_after_packets_;
   QuicTime::Delta yield_after_duration_;
 
   // Set if all sessions should be closed when any local IP address changes.
   const bool close_sessions_on_ip_change_;
 
   // Set if migration should be attempted on active sessions when primary
   // interface changes.
   const bool migrate_sessions_on_network_change_;
 
+  // Set if early migration should be attempted when the connection
+  // experiences poor connectivity.
+  const bool migrate_sessions_early_;
+
   // Each profile will (probably) have a unique port_seed_ value.  This value
   // is used to help seed a pseudo-random number generator (PortSuggester) so
   // that we consistently (within this profile) suggest the same ephemeral
   // port when we re-connect to any given server/port.  The differences between
   // profiles (probablistically) prevent two profiles from colliding in their
   // ephemeral port requests.
   uint64_t port_seed_;
 
   // Local address of socket that was created in CreateSession.
   IPEndPoint local_address_;
   bool check_persisted_supports_quic_;
   bool has_initialized_data_;
   std::set<HostPortPair> quic_supported_servers_at_startup_;
 
   NetworkConnection network_connection_;
 
   QuicPromisedByUrlMap promised_by_url_;
 
   base::TaskRunner* task_runner_;
 
   base::WeakPtrFactory<QuicStreamFactory> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicStreamFactory);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_STREAM_FACTORY_H_