OnReceivedUplinkPacketLossFraction() receives [const rtc::Optional<float>&]

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

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 103 matching lines @@
 void AudioEncoderCopyRed::SetMaxPlaybackRate(int frequency_hz) {
   speech_encoder_->SetMaxPlaybackRate(frequency_hz);
 }
 
 rtc::ArrayView<std::unique_ptr<AudioEncoder>>
 AudioEncoderCopyRed::ReclaimContainedEncoders() {
   return rtc::ArrayView<std::unique_ptr<AudioEncoder>>(&speech_encoder_, 1);
 }
 
 void AudioEncoderCopyRed::OnReceivedUplinkPacketLossFraction(
-    float uplink_packet_loss_fraction) {
+    const rtc::Optional<float>& uplink_packet_loss_fraction) {
   speech_encoder_->OnReceivedUplinkPacketLossFraction(
       uplink_packet_loss_fraction);
 }
 
 void AudioEncoderCopyRed::OnReceivedUplinkBandwidth(
     int target_audio_bitrate_bps,
     rtc::Optional<int64_t> probing_interval_ms) {
   speech_encoder_->OnReceivedUplinkBandwidth(target_audio_bitrate_bps,
                                              probing_interval_ms);
 }
 
 }  // namespace webrtc