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 <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;
+class VirtualAudioInputStream;
 
 // AudioManagerBase provides AudioManager functions common for all platforms.
 class MEDIA_EXPORT AudioManagerBase : public AudioManager {
  public:
   // Name of the generic "default" device.
   static const char kDefaultDeviceName[];
   // Unique Id of the generic "default" device.
   static const char kDefaultDeviceId[];
 
   virtual ~AudioManagerBase();
@@ skipping 112 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_;
 
+  // Currently active VirtualAudioInputStream. When this is set, we will
+  // create all audio output streams as virtual streams so as to redirect them
+  // to this virtual input stream for tab audio capture.

[Alpha Left Google, 2012/11/28 21:26:51]

No need to mention tab audio capture here.

+  VirtualAudioInputStream* virtual_audio_input_stream_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_