Cast: Don't cancel re-transmission for some cases

media/cast/transport/rtp_sender/rtp_sender.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 "media/cast/transport/rtp_sender/rtp_sender.h"
 
 #include "base/logging.h"
 #include "base/rand_util.h"
 #include "media/cast/transport/cast_transport_defines.h"
 #include "media/cast/transport/pacing/paced_sender.h"
@@ skipping 56 matching lines @@
   packetizer_.reset(new RtpPacketizer(transport_, storage_.get(), config_));
   return true;
 }
 
 void RtpSender::SendFrame(const EncodedFrame& frame) {
   DCHECK(packetizer_);
   packetizer_->SendFrameAsPackets(frame);
 }
 
 void RtpSender::ResendPackets(
-    const MissingFramesAndPacketsMap& missing_frames_and_packets) {
+    const MissingFramesAndPacketsMap& missing_frames_and_packets,
+    bool cancel_rtx_if_not_in_list) {
   DCHECK(storage_);
   // Iterate over all frames in the list.
   for (MissingFramesAndPacketsMap::const_iterator it =
            missing_frames_and_packets.begin();
        it != missing_frames_and_packets.end();
        ++it) {
     SendPacketVector packets_to_resend;
     uint8 frame_id = it->first;
     // Set of packets that the receiver wants us to re-send.
     // If empty, we need to re-send all packets for this frame.
     const PacketIdSet& missing_packet_set = it->second;
 
     const SendPacketVector* stored_packets = storage_->GetFrame8(frame_id);
     if (!stored_packets)
       continue;
 
     for (SendPacketVector::const_iterator it = stored_packets->begin();
          it != stored_packets->end(); ++it) {
       const PacketKey& packet_key = it->first;
       const uint16 packet_id = packet_key.second.second;
 
       // If the resend request doesn't include this packet then cancel
       // re-transmission already in queue.
-      if (!missing_packet_set.empty() &&
+      if (cancel_rtx_if_not_in_list &&
+          !missing_packet_set.empty() &&
           missing_packet_set.find(packet_id) == missing_packet_set.end()) {
         transport_->CancelSendingPacket(it->first);
       } else {
         // Resend packet to the network.
         VLOG(3) << "Resend " << static_cast<int>(frame_id) << ":"
                 << packet_id;
         // Set a unique incremental sequence number for every packet.
         PacketRef packet_copy = FastCopyPacket(it->second);
         UpdateSequenceNumber(&packet_copy->data);
         packets_to_resend.push_back(std::make_pair(packet_key, packet_copy));
       }
     }
     transport_->ResendPackets(packets_to_resend);
   }
 }
 
 void RtpSender::UpdateSequenceNumber(Packet* packet) {
   uint16 new_sequence_number = packetizer_->NextSequenceNumber();
   int index = 2;
   (*packet)[index] = (static_cast<uint8>(new_sequence_number));
   (*packet)[index + 1] = (static_cast<uint8>(new_sequence_number >> 8));
 }
 
 }  // namespace transport
 }  //  namespace cast
 }  // namespace media