Adds support for capture device enumeration on Windows.

media/audio/win/audio_manager_win.h

 // Copyright (c) 2011 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 MEDIA_AUDIO_WIN_AUDIO_MANAGER_WIN_H_
 #define MEDIA_AUDIO_WIN_AUDIO_MANAGER_WIN_H_
 
 #include <windows.h>
+#include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
 #include "media/audio/audio_manager_base.h"
 
 class PCMWaveOutAudioOutputStream;
 
 // Windows implementation of the AudioManager singleton. This class is internal
 // to the audio output and only internal users can call methods not exposed by
 // the AudioManager class.
-class AudioManagerWin : public AudioManagerBase {
+class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
  public:
   AudioManagerWin();
   // Implementation of AudioManager.
   virtual bool HasAudioOutputDevices() OVERRIDE;
   virtual bool HasAudioInputDevices() OVERRIDE;
   virtual AudioOutputStream* MakeAudioOutputStream(
       const AudioParameters& params) OVERRIDE;
   virtual AudioInputStream* MakeAudioInputStream(
       const AudioParameters& params, const std::string& device_id) OVERRIDE;
   virtual void MuteAll() OVERRIDE;
   virtual void UnMuteAll() OVERRIDE;
   virtual string16 GetAudioInputDeviceModel() OVERRIDE;
   virtual bool CanShowAudioInputSettings() OVERRIDE;
   virtual void ShowAudioInputSettings() OVERRIDE;
   virtual void GetAudioInputDeviceNames(media::AudioDeviceNames* device_names)
       OVERRIDE;
 
   // Windows-only methods to free a stream created in MakeAudioStream. These
   // are called internally by the audio stream when it has been closed.
   void ReleaseOutputStream(AudioOutputStream* stream);
 
   // Called internally by the audio stream when it has been closed.
   void ReleaseInputStream(AudioInputStream* stream);
 
  private:
+  enum EnumerationType {
+    kUninitializedEnumeration = 0,
+    kMMDeviceEnumeration,
+    kWaveEnumeration,
+  };
+
   virtual ~AudioManagerWin();
 
+  // Allow unit test to modify the utilized enumeration API.
+  friend class AudioInputDeviceTest;
+
+  EnumerationType enumeration_type_;
+  EnumerationType enumeration_type() { return enumeration_type_; }
+  void SetEnumerationType(EnumerationType type) {
+    enumeration_type_ = type;
+  }
+
   // Number of currently open output streams.
   int num_output_streams_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerWin);
 };
 
 #endif  // MEDIA_AUDIO_WIN_AUDIO_MANAGER_WIN_H_