Pass more detailed audio hardware configuration information to the renderer

media/audio/mac/audio_manager_mac.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_MAC_AUDIO_MANAGER_MAC_H_
 #define MEDIA_AUDIO_MAC_AUDIO_MANAGER_MAC_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop_proxy.h"
@@ skipping 20 matching lines @@
   // Implementation of AudioManagerBase.
   virtual AudioOutputStream* MakeLinearOutputStream(
       const AudioParameters& params) OVERRIDE;
   virtual AudioOutputStream* MakeLowLatencyOutputStream(
       const AudioParameters& params) OVERRIDE;
   virtual AudioInputStream* MakeLinearInputStream(
       const AudioParameters& params, const std::string& device_id) OVERRIDE;
   virtual AudioInputStream* MakeLowLatencyInputStream(
       const AudioParameters& params, const std::string& device_id) OVERRIDE;
 
+  static bool GetDefaultOutputDevice(AudioDeviceID* device);
+
+  static bool GetDefaultOutputChannels(int* channels,
+                                       int* channels_per_frame);
+
+  static bool GetDeviceChannels(AudioDeviceID device,
+                                AudioObjectPropertyScope scope,
+                                int* channels,
+                                int* channels_per_frame);
+
  protected:
   virtual ~AudioManagerMac();
 
   virtual AudioParameters GetPreferredOutputStreamParameters(
       const AudioParameters& input_params) OVERRIDE;
 
  private:
   // Helper methods for constructing AudioDeviceListenerMac on the audio thread.
   void CreateDeviceListener();
   void DestroyDeviceListener();
   void DelayedDeviceChange();
 
   scoped_ptr<AudioDeviceListenerMac> output_device_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerMac);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_MANAGER_MAC_H_