Start using the loss timeout in QuicSentPacketManager and add a mock

net/quic/quic_sent_packet_manager.h

 // Copyright 2013 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_SENT_PACKET_MANAGER_H_
 #define NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
 
 #include <deque>
 #include <list>
 #include <map>
@@ skipping 157 matching lines @@
 
  private:
   friend class test::QuicConnectionPeer;
   friend class test::QuicSentPacketManagerPeer;
 
   enum ReceivedByPeer {
     RECEIVED_BY_PEER,
     NOT_RECEIVED_BY_PEER,
   };
 
+  // The retransmission timer is a single timer which switches modes depending
+  // upon connection state.
   enum RetransmissionTimeoutMode {
+    // A conventional TCP style RTO.
     RTO_MODE,
+    // A tail loss probe.  By default, QUIC sends up to two before RTOing.
     TLP_MODE,
+    // Retransmission of handshake packets prior to handshake completion.
     HANDSHAKE_MODE,
+    // Re-invoke the loss detection when a packet is not acked before the
+    // loss detection algorithm expects.
+    LOSS_MODE,
   };
 
   typedef linked_hash_map<QuicPacketSequenceNumber,
                           TransmissionType> PendingRetransmissionMap;
 
   // Process the incoming ack looking for newly ack'd data packets.
   void HandleAckForSentPackets(const ReceivedPacketInfo& received_info);
 
   // Called when a packet is timed out, such as an RTO.  Removes the bytes from
   // the congestion manager, but does not change the congestion window size.
@@ skipping 84 matching lines @@
   // Maximum number of tail loss probes to send before firing an RTO.
   size_t max_tail_loss_probes_;
   bool using_pacing_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSentPacketManager);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_