Begin adding support for tab mirroring via the MediaStream audio/video capturing

content/browser/renderer_host/media/audio_input_device_manager.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.
 //
 // AudioInputDeviceManager manages the audio input devices. In particular it
 // communicates with MediaStreamManager and AudioInputRendererHost on the
 // browser IO thread, handles queries like enumerate/open/close from
 // MediaStreamManager and start/stop from AudioInputRendererHost.
 // The work for enumerate/open/close is handled asynchronously on Media Stream
 // device thread, while start/stop are synchronous on the IO thread.
@@ skipping 11 matching lines @@
 #include "media/audio/audio_device_name.h"
 
 namespace media {
 class AudioManager;
 }
 
 namespace media_stream {
 
 class AudioInputDeviceManagerEventHandler;
 
-class CONTENT_EXPORT AudioInputDeviceManager
-    : public base::RefCountedThreadSafe<AudioInputDeviceManager>,
-      public MediaStreamProvider {
+class CONTENT_EXPORT AudioInputDeviceManager : public MediaStreamProvider {
  public:
   // Calling Start() with this kFakeOpenSessionId will open the default device,
   // even though Open() has not been called. This is used to be able to use the
   // AudioInputDeviceManager before MediaStream is implemented.
   static const int kFakeOpenSessionId;
 
-  explicit AudioInputDeviceManager(media::AudioManager* audio_manager);
+  AudioInputDeviceManager(media::AudioManager* audio_manager,
+                          media_stream::MediaStreamType device_type);
 
   // MediaStreamProvider implementation, called on IO thread.
   virtual void Register(MediaStreamProviderListener* listener,
                         base::MessageLoopProxy* device_thread_loop) OVERRIDE;
   virtual void Unregister() OVERRIDE;
   virtual void EnumerateDevices() OVERRIDE;
   virtual int Open(const StreamDeviceInfo& device) OVERRIDE;
   virtual void Close(int session_id) OVERRIDE;
 
   // Functions used by AudioInputRenderHost, called on IO thread.
   // Start the device referenced by the session id.
   void Start(int session_id,
              AudioInputDeviceManagerEventHandler* event_handler);
   // Stop the device referenced by the session id.
   void Stop(int session_id);
 
  private:
-  friend class base::RefCountedThreadSafe<AudioInputDeviceManager>;
   virtual ~AudioInputDeviceManager();
 
   // Executed on media stream device thread.
   void EnumerateOnDeviceThread();
   void OpenOnDeviceThread(int session_id, const StreamDeviceInfo& device);
   void CloseOnDeviceThread(int session_id);
 
   // Executed on IO thread to call Listener.
   void DevicesEnumeratedOnIOThread(StreamDeviceInfoArray* devices);
   void OpenedOnIOThread(int session_id);
   void ClosedOnIOThread(int session_id);
 
   bool IsOnDeviceThread() const;
 
   // Only accessed on Browser::IO thread.
   MediaStreamProviderListener* listener_;
   int next_capture_session_id_;
   typedef std::map<int, AudioInputDeviceManagerEventHandler*> EventHandlerMap;
   EventHandlerMap event_handlers_;
 
   // Only accessed from media stream device thread.
   typedef std::map<int, media::AudioDeviceName> AudioInputDeviceMap;
   AudioInputDeviceMap devices_;
-  media::AudioManager* audio_manager_;
+  media::AudioManager* const audio_manager_;
+
+  // The type of audio input devices managed by this instance (e.g., user
+  // audio capture, tab audio output).
+  const media_stream::MediaStreamType device_type_;
 
   // The message loop of media stream device thread that this object runs on.
   scoped_refptr<base::MessageLoopProxy> device_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioInputDeviceManager);
 };
 
 }  // namespace media_stream
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_DEVICE_MANAGER_H_