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

net/quic/quic_connection.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.
 //
 // The entity that handles framing writes for a Quic client or server.
 // Each QuicSession will have a connection associated with it.
 //
 // On the server side, the Dispatcher handles the raw reads, and hands off
 // packets via ProcessUdpPacket for framing and processing.
 //
@@ skipping 485 matching lines @@
   bool HasQueuedData() const;
 
   // Sets the overall and idle state connection timeouts.
   void SetNetworkTimeouts(QuicTime::Delta overall_timeout,
                           QuicTime::Delta idle_timeout);
 
   // If the connection has timed out, this will close the connection.
   // Otherwise, it will reschedule the timeout alarm.
   void CheckForTimeout();
 
-  // Sends a ping, and resets the ping alarm.
-  void SendPing();
+  // Sends a ping, and resets the ping alarm. If |force| is false,
+  // only sends a ping if the retransmission alarm is not running.
+  void SendPing(bool force);
 
   // Sets up a packet with an QuicAckFrame and sends it out.
   void SendAck();
 
   // Called when an RTO fires.  Resets the retransmission alarm if there are
   // remaining unacked packets.
   void OnRetransmissionTimeout();
 
   // Called when a data packet is sent. Starts an alarm if the data sent in
   // |packet_number| was FEC protected.
@@ skipping 468 matching lines @@
 
   // Whether a GoAway has been received.
   bool goaway_received_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicConnection);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CONNECTION_H_