Migrates QUIC sessions to a new network when old network is (about to be) disconnected.

chrome/browser/io_thread.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 CHROME_BROWSER_IO_THREAD_H_
 #define CHROME_BROWSER_IO_THREAD_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 223 matching lines @@
     Optional<bool> quic_delay_tcp_race;
     Optional<size_t> quic_max_packet_length;
     net::QuicTagVector quic_connection_options;
     Optional<std::string> quic_user_agent_id;
     Optional<net::QuicVersionVector> quic_supported_versions;
     Optional<net::HostPortPair> origin_to_force_quic_on;
     Optional<bool> quic_close_sessions_on_ip_change;
     Optional<int> quic_idle_connection_timeout_seconds;
     Optional<bool> quic_disable_preconnect_if_0rtt;
     std::unordered_set<std::string> quic_host_whitelist;
+    Optional<bool> quic_migrate_sessions_on_network_change;
     bool enable_user_alternate_protocol_ports;
     // NetErrorTabHelper uses |dns_probe_service| to send DNS probes when a
     // main frame load fails with a DNS error in order to provide more useful
     // information to the renderer so it can show a more specific error page.
     scoped_ptr<chrome_browser_net::DnsProbeService> dns_probe_service;
   };
 
   // |net_log| must either outlive the IOThread or be NULL.
   IOThread(PrefService* local_state,
            policy::PolicyService* policy_service,
@@ skipping 207 matching lines @@
 
   // Returns true if PreConnect should be disabled if QUIC can do 0RTT.
   static bool ShouldQuicDisablePreConnectIfZeroRtt(
       const VariationParameters& quic_trial_params);
 
   // Returns the set of hosts to whitelist for QUIC.
   static std::unordered_set<std::string> GetQuicHostWhitelist(
       const base::CommandLine& command_line,
       const VariationParameters& quic_trial_params);
 
+  // Returns true if QUIC should migrate sessions when primary network
+  // changes.
+  static bool ShouldQuicMigrateSessionsOnNetworkChange(
+      const VariationParameters& quic_trial_params);
+
   // Returns the maximum length for QUIC packets, based on any flags in
   // |command_line| or the field trial.  Returns 0 if there is an error
   // parsing any of the options, or if the default value should be used.
   static size_t GetQuicMaxPacketLength(
       const base::CommandLine& command_line,
       const VariationParameters& quic_trial_params);
 
   // Returns the QUIC versions specified by any flags in |command_line|
   // or |quic_trial_params|.
   static net::QuicVersion GetQuicVersion(
@@ skipping 96 matching lines @@
   bool is_quic_allowed_by_policy_;
 
   const base::TimeTicks creation_time_;
 
   base::WeakPtrFactory<IOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOThread);
 };
 
 #endif  // CHROME_BROWSER_IO_THREAD_H_