Update smoothed bitrate.

webrtc/modules/audio_coding/codecs/cng/audio_encoder_cng.h

Index: webrtc/modules/audio_coding/codecs/cng/audio_encoder_cng.h
diff --git a/webrtc/modules/audio_coding/codecs/cng/audio_encoder_cng.h b/webrtc/modules/audio_coding/codecs/cng/audio_encoder_cng.h
index 8cec52c394955537be072615ba41b0fb9842a381..9535c0a83c3a68037e332b8d2b9cf6edd239d063 100644
--- a/webrtc/modules/audio_coding/codecs/cng/audio_encoder_cng.h
+++ b/webrtc/modules/audio_coding/codecs/cng/audio_encoder_cng.h
@@ -65,7 +65,9 @@ class AudioEncoderCng final : public AudioEncoder {
       override;
   void OnReceivedUplinkPacketLossFraction(
       float uplink_packet_loss_fraction) override;
-  void OnReceivedTargetAudioBitrate(int target_audio_bitrate_bps) override;
+  void OnReceivedTargetAudioBitrate(
+      int target_audio_bitrate_bps,
+      rtc::Optional<int64_t> probing_interval_ms) override;
 
  private:
   EncodedInfo EncodePassive(size_t frames_to_encode,