Start using the loss timeout in QuicSentPacketManager and add a mock

net/quic/congestion_control/loss_detection_interface.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.
 //
 // The pure virtual class for send side loss detection algorithm.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_LOSS_DETECTION_INTERFACE_H_
 #define NET_QUIC_CONGESTION_CONTROL_LOSS_DETECTION_INTERFACE_H_
 
 #include "base/basictypes.h"
@@ skipping 10 matching lines @@
   static LossDetectionInterface* Create();
 
   virtual ~LossDetectionInterface() {}
 
   // Called when a new ack arrives or the loss alarm fires.
   virtual SequenceNumberSet DetectLostPackets(
       const QuicUnackedPacketMap& unacked_packets,
       const QuicTime& time,
       QuicPacketSequenceNumber largest_observed,
       QuicTime::Delta srtt) = 0;
+
+  // Get the time the LossDetectionAlgorithm wants to re-evaluate losses.
+  // Returns QuicTime::Zero if no alarm needs to be set.
+  virtual QuicTime GetLossTimeout() const = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_LOSS_DETECTION_INTERFACE_H_