Browser-wide audio mirroring for TabCapture API

media/audio/audio_manager_base.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 MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
 #define MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
 
 #include <map>
+#include <set>
 #include <string>
 #include <utility>
 
 #include "base/atomic_ref_count.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
 #include "media/audio/audio_manager.h"
 
 #if defined(OS_WIN)
 #include "base/win/scoped_com_initializer.h"
 #endif
 
 namespace base {
 class Thread;
 }
 
 namespace media {
 
 class AudioOutputDispatcher;
 
 // AudioManagerBase provides AudioManager functions common for all platforms.
 class MEDIA_EXPORT AudioManagerBase : public AudioManager {
  public:
+  typedef std::set<AudioOutputStream*> AudioOutputStreamList;
+
   // Name of the generic "default" device.
   static const char kDefaultDeviceName[];
   // Unique Id of the generic "default" device.
   static const char kDefaultDeviceId[];
 
   virtual ~AudioManagerBase();
 
   virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() OVERRIDE;
 
   virtual string16 GetAudioInputDeviceModel() OVERRIDE;
@@ skipping 15 matching lines @@
 
   virtual bool IsRecordingInProcess() OVERRIDE;
 
   // Called internally by the audio stream when it has been closed.
   virtual void ReleaseOutputStream(AudioOutputStream* stream);
   virtual void ReleaseInputStream(AudioInputStream* stream);
 
   void IncreaseActiveInputStreamCount();
   void DecreaseActiveInputStreamCount();
 
+  // These must be called on the audio thread.
+  void RegisterVirtualAudioOutputStream(AudioOutputStream* stream);
+  void UnregisterVirtualAudioOutputStream(AudioOutputStream* stream);
+  AudioOutputStreamList GetVirtualAudioOutputStreams();
+
   // Creates the output stream for the |AUDIO_PCM_LINEAR| format. The legacy
   // name is also from |AUDIO_PCM_LINEAR|.
   virtual AudioOutputStream* MakeLinearOutputStream(
       const AudioParameters& params) = 0;
 
   // Creates the output stream for the |AUDIO_PCM_LOW_LATENCY| format.
   virtual AudioOutputStream* MakeLowLatencyOutputStream(
       const AudioParameters& params) = 0;
 
   // Creates the input stream for the |AUDIO_PCM_LINEAR| format. The legacy
@@ skipping 73 matching lines @@
 
   // Thread used to interact with audio streams created by this audio manager.
   scoped_ptr<base::Thread> audio_thread_;
   mutable base::Lock audio_thread_lock_;
 
   // The message loop of the audio thread this object runs on. Used for internal
   // tasks which run on the audio thread even after Shutdown() has been started
   // and GetMessageLoop() starts returning NULL.
   scoped_refptr<base::MessageLoopProxy> message_loop_;
 
+  AudioOutputStreamList virtual_audio_output_streams_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_