Remove AudioDeviceObserver and make ADM not inherit from the Module interface.

modules/audio_device/dummy/file_audio_device.h

 /*
  *  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 114 matching lines @@
   int32_t SetStereoPlayout(bool enable) override;
   int32_t StereoPlayout(bool& enabled) const override;
   int32_t StereoRecordingIsAvailable(bool& available) override;
   int32_t SetStereoRecording(bool enable) override;
   int32_t StereoRecording(bool& enabled) const override;
 
   // Delay information and control
   int32_t PlayoutDelay(uint16_t& delayMS) const override;
   int32_t RecordingDelay(uint16_t& delayMS) const override;
 
-  bool PlayoutWarning() const override;
-  bool PlayoutError() const override;
-  bool RecordingWarning() const override;
-  bool RecordingError() const override;
-  void ClearPlayoutWarning() override;
-  void ClearPlayoutError() override;
-  void ClearRecordingWarning() override;
-  void ClearRecordingError() override;
-
   void AttachAudioBuffer(AudioDeviceBuffer* audioBuffer) override;
 
  private:
   static bool RecThreadFunc(void*);
   static bool PlayThreadFunc(void*);
   bool RecThreadProcess();
   bool PlayThreadProcess();
 
   int32_t _playout_index;
   int32_t _record_index;
@@ skipping 19 matching lines @@
 
   FileWrapper& _outputFile;
   FileWrapper& _inputFile;
   std::string _outputFilename;
   std::string _inputFilename;
 };
 
 }  // namespace webrtc
 
 #endif  // AUDIO_DEVICE_FILE_AUDIO_DEVICE_H_