Update smoothed bitrate.

webrtc/modules/audio_coding/codecs/red/audio_encoder_copy_red.h

Index: webrtc/modules/audio_coding/codecs/red/audio_encoder_copy_red.h
diff --git a/webrtc/modules/audio_coding/codecs/red/audio_encoder_copy_red.h b/webrtc/modules/audio_coding/codecs/red/audio_encoder_copy_red.h
index d069cbef158e5ba5eea8694b7acd599a54a0cf71..5d2f701a7ebf770cf396ee35b28970e5830c5f5f 100644
--- a/webrtc/modules/audio_coding/codecs/red/audio_encoder_copy_red.h
+++ b/webrtc/modules/audio_coding/codecs/red/audio_encoder_copy_red.h
@@ -53,7 +53,9 @@ class AudioEncoderCopyRed 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;
 
  protected:
   EncodedInfo EncodeImpl(uint32_t rtp_timestamp,