Early connection migration in QUIC.

net/quic/quic_connection.cc

 // 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.
 
 #include "net/quic/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>
@@ skipping 1852 matching lines @@
 
   packet_generator_.SetShouldSendAck(true);
 }
 
 void QuicConnection::OnRetransmissionTimeout() {
   if (!sent_packet_manager_.HasUnackedPackets()) {
     return;
   }
 
   sent_packet_manager_.OnRetransmissionTimeout();
+  // Migrate connection if appropriate before sending retransmissions.
+  if (sent_packet_manager_.IsPeerMaybeUnreachable()) {
+    visitor_->MaybeMigrateConnection();
+  }
   WriteIfNotBlocked();
 
   // A write failure can result in the connection being closed, don't attempt to
   // write further packets, or to set alarms.
   if (!connected_) {
     return;
   }
 
   // In the TLP case, the SentPacketManager gives the connection the opportunity
   // to send new data before retransmitting.
@@ skipping 558 matching lines @@
 void QuicConnection::OnPathClosed(QuicPathId path_id) {
   // Stop receiving packets on this path.
   framer_.OnPathClosed(path_id);
 }
 
 bool QuicConnection::ack_frame_updated() const {
   return received_packet_manager_.ack_frame_updated();
 }
 
 }  // namespace net