Adding packet overhead to audio network adaptor.

webrtc/modules/audio_coding/audio_network_adaptor/controller.h

Index: webrtc/modules/audio_coding/audio_network_adaptor/controller.h
diff --git a/webrtc/modules/audio_coding/audio_network_adaptor/controller.h b/webrtc/modules/audio_coding/audio_network_adaptor/controller.h
index 07806aa000ca85e3ad723d15ab689a3edb7867a1..4f97804317cfcff59c62642d7b5b438ff1592b2d 100644
--- a/webrtc/modules/audio_coding/audio_network_adaptor/controller.h
+++ b/webrtc/modules/audio_coding/audio_network_adaptor/controller.h
@@ -25,6 +25,7 @@ class Controller {
     rtc::Optional<float> uplink_packet_loss_fraction;
     rtc::Optional<int> target_audio_bitrate_bps;
     rtc::Optional<int> rtt_ms;
+    rtc::Optional<size_t> overhead_bytes_per_packet;
   };
 
   virtual ~Controller() = default;