Start using the loss timeout in QuicSentPacketManager and add a mock

net/quic/congestion_control/tcp_loss_algorithm.cc

 // 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.
 
 #include "net/quic/congestion_control/tcp_loss_algorithm.h"
 
 #include "net/quic/quic_protocol.h"
 
 namespace net {
 
@@ skipping 30 matching lines @@
     if (it->second.nack_count < num_nacks_needed) {
       continue;
     }
 
     lost_packets.insert(it->first);
   }
 
   return lost_packets;
 }
 
+QuicTime TCPLossAlgorithm::GetLossTimeout() const {
+  return QuicTime::Zero();
+}
+
 }  // namespace net