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

modules/audio_device/win/audio_device_core_win.h

 /*
  *  Copyright (c) 2012 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 160 matching lines @@
     virtual int32_t SetStereoRecording(bool enable);
     virtual int32_t StereoRecording(bool& enabled) const;
 
     // Delay information and control
     virtual int32_t PlayoutDelay(uint16_t& delayMS) const;
     virtual int32_t RecordingDelay(uint16_t& delayMS) const;
 
     virtual int32_t EnableBuiltInAEC(bool enable);
 
 public:
-    virtual bool PlayoutWarning() const;
-    virtual bool PlayoutError() const;
-    virtual bool RecordingWarning() const;
-    virtual bool RecordingError() const;
-    virtual void ClearPlayoutWarning();
-    virtual void ClearPlayoutError();
-    virtual void ClearRecordingWarning();
-    virtual void ClearRecordingError();
-
-public:
     virtual void AttachAudioBuffer(AudioDeviceBuffer* audioBuffer);
 
 private:
     bool KeyPressed() const;
 
 private:    // avrt function pointers
     PAvRevertMmThreadCharacteristics    _PAvRevertMmThreadCharacteristics;
     PAvSetMmThreadCharacteristicsA      _PAvSetMmThreadCharacteristicsA;
     PAvSetMmThreadPriority              _PAvSetMmThreadPriority;
     HMODULE                             _avrtLibrary;
@@ skipping 124 matching lines @@
 
     bool                                    _usingInputDeviceIndex;
     bool                                    _usingOutputDeviceIndex;
     AudioDeviceModule::WindowsDeviceType    _inputDevice;
     AudioDeviceModule::WindowsDeviceType    _outputDevice;
     uint16_t                          _inputDeviceIndex;
     uint16_t                          _outputDeviceIndex;
 
     bool                                    _AGC;
 
-    uint16_t                          _playWarning;
-    uint16_t                          _playError;
-    uint16_t                          _recWarning;
-    uint16_t                          _recError;
-
     uint16_t                          _playBufDelay;
 
     uint16_t                          _newMicLevel;
 
     mutable char                            _str[512];
 };
 
 #endif    // #if (_MSC_VER >= 1400)
 
 }  // namespace webrtc
 
 #endif  // AUDIO_DEVICE_AUDIO_DEVICE_CORE_WIN_H_