[Mojo Video Capture] Add content_browsertest for exercising video capture

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/GetOpenedDeviceInfoById from MediaStreamManager and
 // GetOpenedDeviceInfoById from AudioInputRendererHost.
 // The work for enumerate/open/close is handled asynchronously on Media Stream
@@ skipping 30 matching lines @@
   static const int kFakeOpenSessionId;
 
   explicit AudioInputDeviceManager(media::AudioManager* audio_manager);
 
   // Gets the opened device info by |session_id|. Returns NULL if the device
   // is not opened, otherwise the opened device. Called on IO thread.
   const StreamDeviceInfo* GetOpenedDeviceInfoById(int session_id);
 
   // MediaStreamProvider implementation.
   void RegisterListener(MediaStreamProviderListener* listener) override;
-  void UnregisterListener() override;
-  int Open(const StreamDeviceInfo& device) override;
+  void UnregisterListener(MediaStreamProviderListener* listener) override;
+  int Open(const MediaStreamDevice& device) override;
   void Close(int session_id) override;
 
 #if defined(OS_CHROMEOS)
   // Registers and unregisters that a stream using keyboard mic has been opened
   // or closed. Keeps count of how many such streams are open and activates and
   // inactivates the keyboard mic accordingly. The (in)activation is done on the
   // UI thread and for the register case a callback must therefor be provided
   // which is called when activated.
   void RegisterKeyboardMicStream(const base::Closure& callback);
   void UnregisterKeyboardMicStream();
 #endif
 
  private:
   typedef std::vector<StreamDeviceInfo> StreamDeviceList;
   ~AudioInputDeviceManager() override;
 
   // Opens the device on media stream device thread.
-  void OpenOnDeviceThread(int session_id, const StreamDeviceInfo& info);
+  void OpenOnDeviceThread(int session_id, const MediaStreamDevice& device);
 
   // Callback used by OpenOnDeviceThread(), called with the session_id
   // referencing the opened device on IO thread.
   void OpenedOnIOThread(int session_id, const StreamDeviceInfo& info);
   // Callback used by CloseOnDeviceThread(), called with the session_id
   // referencing the closed device on IO thread.
   void ClosedOnIOThread(MediaStreamType type, int session_id);
 
   // Verifies that the calling thread is media stream device thread.
   bool IsOnDeviceThread() const;
 
   // Helper to return iterator to the device referenced by |session_id|. If no
   // device is found, it will return devices_.end().
   StreamDeviceList::iterator GetDevice(int session_id);
 
 #if defined(OS_CHROMEOS)
   // Calls Cras audio handler and sets keyboard mic active status.
   void SetKeyboardMicStreamActiveOnUIThread(bool active);
 #endif
 
   // Only accessed on Browser::IO thread.
-  MediaStreamProviderListener* listener_;
+  base::ObserverList<MediaStreamProviderListener> listeners_;
   int next_capture_session_id_;
   StreamDeviceList devices_;
 
 #if defined(OS_CHROMEOS)
   // Keeps count of how many streams are using keyboard mic.
   int keyboard_mic_streams_count_;
 #endif
 
   media::AudioManager* const audio_manager_;  // Weak.
 
   // The message loop of media stream device thread that this object runs on.
   scoped_refptr<base::SingleThreadTaskRunner> device_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioInputDeviceManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_DEVICE_MANAGER_H_