Cleanup in QUIC to merge the previous_transmissions_map in

net/quic/test_tools/quic_sent_packet_manager_peer.cc

 // 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.
 
 #include "net/quic/test_tools/quic_sent_packet_manager_peer.h"
 
 #include "base/stl_util.h"
 #include "net/quic/congestion_control/send_algorithm_interface.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_sent_packet_manager.h"
@@ skipping 31 matching lines @@
     QuicSentPacketManager* sent_packet_manager) {
   return sent_packet_manager->rtt_sample_;
 }
 
 // static
 bool QuicSentPacketManagerPeer::IsRetransmission(
     QuicSentPacketManager* sent_packet_manager,
     QuicPacketSequenceNumber sequence_number) {
   DCHECK(sent_packet_manager->HasRetransmittableFrames(sequence_number));
   return sent_packet_manager->HasRetransmittableFrames(sequence_number) &&
-      ContainsKey(sent_packet_manager->previous_transmissions_map_,
-                  sequence_number);
+      sent_packet_manager->
+          unacked_packets_[sequence_number].previous_transmissions != NULL;
 }
 
 // static
 void QuicSentPacketManagerPeer::MarkForRetransmission(
     QuicSentPacketManager* sent_packet_manager,
     QuicPacketSequenceNumber sequence_number,
     TransmissionType transmission_type) {
   sent_packet_manager->MarkForRetransmission(sequence_number,
                                              transmission_type);
 }
 
 }  // namespace test
 }  // namespace net