Make AudioParameters a class instead of a struct

media/audio/audio_util.h

Index: media/audio/audio_util.h
diff --git a/media/audio/audio_util.h b/media/audio/audio_util.h
index c57f2c2d654b84d269952ffe969bed39e85a1280..5cdc8dcf867147516385939427c713fbbe91a2c9 100644
--- a/media/audio/audio_util.h
+++ b/media/audio/audio_util.h
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "media/base/channel_layout.h"
 #include "media/base/media_export.h"
 
 struct AudioParameters;
@@ -94,8 +95,8 @@ MEDIA_EXPORT double GetAudioInputHardwareSampleRate(
 // at without glitches.  The buffer size is in sample-frames.
 MEDIA_EXPORT size_t GetAudioHardwareBufferSize();
 
-// Returns the number of channels for the specified audio input device.
-MEDIA_EXPORT uint32 GetAudioInputHardwareChannelCount(
+// Returns the channel layout for the specified audio input device.
+MEDIA_EXPORT ChannelLayout GetAudioInputHardwareChannelLayout(
     const std::string& device_id);
 
 // Functions that handle data buffer passed between processes in the shared