[Chromoting] Move DefaultAudioDeviceChangeDetector out of AudioCapturerWin

remoting/host/audio_capturer_win.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef REMOTING_HOST_AUDIO_CAPTURER_WIN_H_
 #define REMOTING_HOST_AUDIO_CAPTURER_WIN_H_
 
 #include <audioclient.h>
 #include <endpointvolume.h>
 #include <mmdeviceapi.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
 #include "base/win/scoped_co_mem.h"
 #include "base/win/scoped_comptr.h"
 #include "remoting/host/audio_capturer.h"
 #include "remoting/host/audio_silence_detector.h"
 #include "remoting/proto/audio.pb.h"
 
 namespace remoting {
 
+class DefaultAudioDeviceChangeDetector;
+
 class AudioCapturerWin : public AudioCapturer {
  public:
   AudioCapturerWin();
   ~AudioCapturerWin() override;
 
   // AudioCapturer interface.
   bool Start(const PacketCapturedCallback& callback) override;
 
  private:
-  // An IMMNotificationClient implementation to detect the event of default
-  // audio device recently changed. If it indicates a changed happend recently,
-  // we need to recreate all audio components.
-  class MMNotificationClient;
-
   // Executes Deinitialize() and Initialize(). If Initialize() function call
   // returns false, Deinitialize() will be called again to ensure we will
   // initialize COM components again.
   bool ResetAndInitialize();
 
   // Resets all COM components to nullptr, so is_initialized() will return
   // false.
   void Deinitialize();
 
   // Initializes default audio device related components. These components must
@@ skipping 23 matching lines @@
   PacketCapturedCallback callback_;
 
   AudioPacket::SamplingRate sampling_rate_;
 
   std::unique_ptr<base::RepeatingTimer> capture_timer_;
   base::TimeDelta audio_device_period_;
 
   AudioSilenceDetector silence_detector_;
 
   base::win::ScopedCoMem<WAVEFORMATEX> wave_format_ex_;
-  base::win::ScopedComPtr<IMMDeviceEnumerator> mm_device_enumerator_;
   base::win::ScopedComPtr<IAudioCaptureClient> audio_capture_client_;
   base::win::ScopedComPtr<IAudioClient> audio_client_;
   base::win::ScopedComPtr<IMMDevice> mm_device_;
   base::win::ScopedComPtr<IAudioEndpointVolume> audio_volume_;
 
-  const std::unique_ptr<MMNotificationClient> mm_notification_client_;
+  std::unique_ptr<DefaultAudioDeviceChangeDetector> default_device_detector_;
 
   HRESULT last_capture_error_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioCapturerWin);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_AUDIO_CAPTURER_WIN_H_