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..b83cce9e766960aa7d41ee09d0dbe67a757ad9e5 100644
--- a/media/audio/audio_util.h
+++ b/media/audio/audio_util.h
@@ -9,10 +9,9 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "media/base/channel_layout.h"
 #include "media/base/media_export.h"
 
-struct AudioParameters;
-
 namespace base {
 class SharedMemory;
 }
@@ -83,10 +82,10 @@ MEDIA_EXPORT void InterleaveFloatToInt16(const std::vector<float*>& source,
                                          size_t number_of_frames);
 
 // Returns the default audio output hardware sample-rate.
-MEDIA_EXPORT double GetAudioHardwareSampleRate();
+MEDIA_EXPORT int GetAudioHardwareSampleRate();
 
 // Returns the audio input hardware sample-rate for the specified device.
-MEDIA_EXPORT double GetAudioInputHardwareSampleRate(
+MEDIA_EXPORT int GetAudioInputHardwareSampleRate(
     const std::string& device_id);
 
 // Returns the optimal low-latency buffer size for the audio hardware.
@@ -94,8 +93,8 @@ 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