Browser-wide audio mirroring for TabCapture API

media/audio/audio_manager_base.h

Index: media/audio/audio_manager_base.h
diff --git a/media/audio/audio_manager_base.h b/media/audio/audio_manager_base.h
index 57b4fe44edb67707401d4b55bd4441dcda9c1dea..9fe3dceace195fe67538a31de8b0e28111fbcbce 100644
--- a/media/audio/audio_manager_base.h
+++ b/media/audio/audio_manager_base.h
@@ -6,6 +6,7 @@
 #define MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
 
 #include <map>
+#include <set>
 #include <string>
 #include <utility>
 
@@ -31,6 +32,8 @@ 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.
@@ -66,6 +69,11 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   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(
@@ -159,6 +167,8 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   // and GetMessageLoop() starts returning NULL.
   scoped_refptr<base::MessageLoopProxy> message_loop_;
 
+  AudioOutputStreamList virtual_audio_output_streams_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 };