Make OverheadObserver::OnOverheadChanged count RTP headers only

webrtc/modules/congestion_controller/congestion_controller.cc

 /*
  *  Copyright (c) 2012 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 288 matching lines @@
     pacer_->Pause();
   }
   {
     rtc::CritScope cs(&critsect_);
     network_state_ = state;
   }
   probe_controller_->OnNetworkStateChanged(state);
   MaybeTriggerOnNetworkChanged();
 }
 
+void CongestionController::SetTransportOverhead(
+    size_t transport_overhead_bytes_per_packet) {
+  transport_feedback_adapter_.SetTransportOverhead(
+      transport_overhead_bytes_per_packet);
+}
+
 void CongestionController::OnSentPacket(const rtc::SentPacket& sent_packet) {
   // We're not interested in packets without an id, which may be stun packets,
   // etc, sent on the same transport.
   if (sent_packet.packet_id == -1)
     return;
   transport_feedback_adapter_.OnSentPacket(sent_packet.packet_id,
                                            sent_packet.send_time_ms);
 }
 
 void CongestionController::OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) {
@@ skipping 62 matching lines @@
 bool CongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }
 
 bool CongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&critsect_);
   return network_state_ == kNetworkDown;
 }
 
 }  // namespace webrtc