Add MuteableAudioOutputStream interface to export SetMute().

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 <memory>
 #include <string>
 #include <unordered_set>
@@ skipping 57 matching lines @@
   virtual AudioOutputStream* MakeLinearOutputStream(
       const AudioParameters& params,
       const LogCallback& log_callback) = 0;
 
   // Creates the output stream for the |AUDIO_PCM_LOW_LATENCY| format.
   virtual AudioOutputStream* MakeLowLatencyOutputStream(
       const AudioParameters& params,
       const std::string& device_id,
       const LogCallback& log_callback) = 0;
 
+  // Creates the output stream for the |AUDIO_BITSTREAM_XXX| format.
+  virtual AudioOutputStream* MakeBitstreamOutputStream(
+      const AudioParameters& params,
+      const std::string& device_id,
+      const LogCallback& log_callback);
+
   // Creates the input stream for the |AUDIO_PCM_LINEAR| format. The legacy
   // name is also from |AUDIO_PCM_LINEAR|.
   virtual AudioInputStream* MakeLinearInputStream(
       const AudioParameters& params,
       const std::string& device_id,
       const LogCallback& log_callback) = 0;
 
   // Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format.
   virtual AudioInputStream* MakeLowLatencyInputStream(
       const AudioParameters& params,
@@ skipping 109 matching lines @@
 
   // Debug recording manager.
   std::unique_ptr<AudioDebugRecordingManager> debug_recording_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_