Tab Audio Capture: Browser-side connect/disconnect functionality.

media/audio/audio_source_diverter.h

+// Copyright (c) 2013 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_SOURCE_DIVERTER_H_
+#define MEDIA_AUDIO_AUDIO_SOURCE_DIVERTER_H_
+
+#include "media/base/media_export.h"
+
+// Audio sources may optionally implement AudioSourceDiverter to temporarily
+// divert audio data to an alternate AudioOutputStream.  This allows the audio
+// data to be plumbed to an alternate consumer; for example, a loopback
+// mechanism for audio mirroring.
+
+namespace media {
+
+class AudioOutputStream;
+class AudioParameters;
+
+class MEDIA_EXPORT AudioSourceDiverter {
+public:
+  // Returns the audio parameters of the divertable audio data.
+  virtual const AudioParameters& GetAudioParameters() = 0;
+
+  // Start providing audio data to the given |to_stream|, which is in an
+  // unopened state.  |to_stream| remains under the control of the
+  // AudioSourceDiverter.
+  virtual void StartDiverting(AudioOutputStream* to_stream) = 0;
+
+  // Stops diverting audio data to the stream.  The AudioSourceDiverter is
+  // responsible for making sure the stream is closed, perhaps asynchronously.
+  virtual void StopDiverting() = 0;
+
+protected:
+  virtual ~AudioSourceDiverter() {}
+};
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_AUDIO_SOURCE_DIVERTER_H_