Set actual transport overhead in rtp_rtcp

webrtc/media/base/mediachannel.h

Index: webrtc/media/base/mediachannel.h
diff --git a/webrtc/media/base/mediachannel.h b/webrtc/media/base/mediachannel.h
index b21919c94a536392cef3089c124f7fa2f2c5e224..48583d4c117f6ab4f3ebc726ea05872b0109ddac 100644
--- a/webrtc/media/base/mediachannel.h
+++ b/webrtc/media/base/mediachannel.h
@@ -405,6 +405,8 @@ class MediaChannel : public sigslot::has_slots<> {
   virtual void OnNetworkRouteChanged(
       const std::string& transport_name,
       const rtc::NetworkRoute& network_route) = 0;
+  // Called when the rtp transport overhead changed.
+  virtual void OnTransportOverheadChange(int transport_overhead_per_packet) = 0;
   // Creates a new outgoing media stream with SSRCs and CNAME as described
   // by sp.
   virtual bool AddSendStream(const StreamParams& sp) = 0;