Revert of Remove audio/video distinction for probe packets.

webrtc/modules/remote_bitrate_estimator/test/packet_sender.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 249 matching lines @@
     return;
   }
   Packets::iterator it = queue_.begin();
   for (; it != queue_.end(); ++it) {
     if ((*it)->send_time_us() > end_of_batch_time_us) {
       break;
     }
   }
   Packets to_transfer;
   to_transfer.splice(to_transfer.begin(), queue_, queue_.begin(), it);
+  for (Packet* packet : to_transfer)
+    packet->set_paced(true);
   bwe_->OnPacketsSent(to_transfer);
   batch->merge(to_transfer, DereferencingComparator<Packet>);
 }
 
 bool PacedVideoSender::TimeToSendPacket(uint32_t ssrc,
                                         uint16_t sequence_number,
                                         int64_t capture_time_ms,
                                         bool retransmission,
                                         int probe_cluster_id) {
   for (Packets::iterator it = pacer_queue_.begin(); it != pacer_queue_.end();
@@ skipping 198 matching lines @@
   RecordBitrate();
 }
 
 uint32_t TcpSender::TargetBitrateKbps() {
   return bitrate_kbps_;
 }
 
 }  // namespace bwe
 }  // namespace testing
 }  // namespace webrtc