message: Remove leftover function signatures.
  Cr-Commit-Position: refs/heads/main@{#39249}
diff: @@ -97,8 +97,6 @@ class WebRtcVoiceEngine final : public VoiceEngineInterface {
  // easily at any time.
  void ApplyOptions(const AudioOptions& options);
  - int CreateVoEChannel();
  -
  webrtc::TaskQueueFactory* const task_queue_factory_;
  std::unique_ptr<rtc::TaskQueue> low_priority_worker_queue_;
  @@ -251,8 +249,6 @@ class WebRtcVoiceMediaChannel final : public VoiceMediaChannel,
  bool MuteStream(uint32_t ssrc, bool mute);
  WebRtcVoiceEngine* engine() { return engine_; }
  - int CreateVoEChannel();
  - bool DeleteVoEChannel(int channel);
  bool SetMaxSendBitrate(int bps);
  void SetupRecording();
  