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

net/http/http_network_session.h

Index: net/http/http_network_session.h
diff --git a/net/http/http_network_session.h b/net/http/http_network_session.h
index 20ee21e2ce1868cf889298f97243b2dceaae8bec..392178ac74c41bff215d13a3816d6b81c6133e47 100644
--- a/net/http/http_network_session.h
+++ b/net/http/http_network_session.h
@@ -173,6 +173,9 @@ class NET_EXPORT HttpNetworkSession
     QuicTagVector quic_connection_options;
     // If true, all QUIC sessions are closed when any local IP address changes.
     bool quic_close_sessions_on_ip_change;
+    // If true, active QUIC sessions may be migrated onto new IPs on network
+    // changes.
+    bool quic_migrate_sessions_on_net_change;
     ProxyDelegate* proxy_delegate;
   };