Fix a flaky EndToEndTest where packet loss is possible with a large

net/quic/quic_sent_packet_manager.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/quic_sent_packet_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
@@ skipping 584 matching lines @@
   for (SequenceNumberSet::const_iterator it = lost_packets.begin();
        it != lost_packets.end(); ++it) {
     QuicPacketSequenceNumber sequence_number = *it;
     const TransmissionInfo& transmission_info =
         unacked_packets_.GetTransmissionInfo(sequence_number);
     // TODO(ianswett): If it's expected the FEC packet may repair the loss, it
     // should be recorded as a loss to the send algorithm, but not retransmitted
     // until it's known whether the FEC packet arrived.
     ++stats_->packets_lost;
     packets_lost_[sequence_number] = transmission_info;
+    DVLOG(1) << ENDPOINT << "Lost packet " << sequence_number;
 
     if (transmission_info.retransmittable_frames != NULL) {
       MarkForRetransmission(sequence_number, LOSS_RETRANSMISSION);
     } else {
       // Since we will not retransmit this, we need to remove it from
       // unacked_packets_.   This is either the current transmission of
       // a packet whose previous transmission has been acked, a packet that has
       // been TLP retransmitted, or an FEC packet.
       unacked_packets_.SetNotPending(sequence_number);
       unacked_packets_.RemovePacket(sequence_number);
@@ skipping 151 matching lines @@
     return;
   }
 
   using_pacing_ = true;
   send_algorithm_.reset(
       new PacingSender(send_algorithm_.release(),
                        QuicTime::Delta::FromMicroseconds(1)));
 }
 
 }  // namespace net