Start using the loss timeout in QuicSentPacketManager and add a mock

net/quic/congestion_control/tcp_loss_algorithm.h

 // Copyright (c) 2014 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_CONGESTION_CONTROL_TCP_LOSS_ALGORITHM_H_
 #define NET_QUIC_CONGESTION_CONTROL_TCP_LOSS_ALGORITHM_H_
 
 #include <algorithm>
 #include <map>
 
@@ skipping 11 matching lines @@
  public:
   TCPLossAlgorithm();
   virtual ~TCPLossAlgorithm() {}
 
   // Uses nack counts to decide when packets are lost.
   virtual SequenceNumberSet DetectLostPackets(
       const QuicUnackedPacketMap& unacked_packets,
       const QuicTime& time,
       QuicPacketSequenceNumber largest_observed,
       QuicTime::Delta srtt) OVERRIDE;
+
+  // Return QuicTime::Zero.
+  virtual QuicTime GetLossTimeout() const OVERRIDE;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_TCP_LOSS_ALGORITHM_H_