Make FlexFEC packets paceable through RTPSender.

webrtc/modules/pacing/packet_router.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 30 matching lines @@
 }
 
 bool PacketRouter::TimeToSendPacket(uint32_t ssrc,
                                     uint16_t sequence_number,
                                     int64_t capture_timestamp,
                                     bool retransmission,
                                     int probe_cluster_id) {
   RTC_DCHECK(pacer_thread_checker_.CalledOnValidThread());
   rtc::CritScope cs(&modules_crit_);
   for (auto* rtp_module : rtp_modules_) {
-    if (rtp_module->SendingMedia() && ssrc == rtp_module->SSRC()) {
+    if (!rtp_module->SendingMedia())
+      continue;
+    if (ssrc == rtp_module->SSRC() || ssrc == rtp_module->FlexfecSsrc()) {
       return rtp_module->TimeToSendPacket(ssrc, sequence_number,
                                           capture_timestamp, retransmission,
                                           probe_cluster_id);
     }
   }
   return true;
 }
 
 size_t PacketRouter::TimeToSendPadding(size_t bytes_to_send,
                                        int probe_cluster_id) {
@@ skipping 38 matching lines @@
   rtc::CritScope cs(&modules_crit_);
   for (auto* rtp_module : rtp_modules_) {
     packet->SetSenderSsrc(rtp_module->SSRC());
     if (rtp_module->SendFeedbackPacket(*packet))
       return true;
   }
   return false;
 }
 
 }  // namespace webrtc