Wire-up audio BWE with overhead.

webrtc/voice_engine/channel.cc

Index: webrtc/voice_engine/channel.cc
diff --git a/webrtc/voice_engine/channel.cc b/webrtc/voice_engine/channel.cc
index dc93dc7e06c30483a10ee658d78da4d9ca2e3c89..056fd782e74c3e694bf5ff038b4a39b4a3370617 100644
--- a/webrtc/voice_engine/channel.cc
+++ b/webrtc/voice_engine/channel.cc
@@ -940,6 +940,7 @@ Channel::Channel(int32_t channelId,
   RtpRtcp::Configuration configuration;
   configuration.audio = true;
   configuration.outgoing_transport = this;
+  configuration.overhead_observer = this;
   configuration.receive_statistics = rtp_receive_statistics_.get();
   configuration.bandwidth_callback = rtcp_observer_.get();
   if (pacing_enabled_) {
@@ -2881,6 +2882,13 @@ void Channel::SetTransportOverhead(int transport_overhead_per_packet) {
   _rtpRtcpModule->SetTransportOverhead(transport_overhead_per_packet);
 }
 
+void Channel::OnOverheadChanged(size_t overhead_bytes_per_packet) {
+  audio_coding_->ModifyEncoder([&](std::unique_ptr<AudioEncoder>* encoder) {
+    if (*encoder)

[the sun, 2016/12/13 16:46:02]

nit: {} for one liners in this file

[michaelt, 2016/12/13 17:04:11]

Done.

+      (*encoder)->OnReceivedOverhead(overhead_bytes_per_packet);
+  });
+}
+
 int Channel::RegisterExternalMediaProcessing(ProcessingTypes type,
                                              VoEMediaProcess& processObject) {
   WEBRTC_TRACE(kTraceInfo, kTraceVoice, VoEId(_instanceId, _channelId),