Make AudioParameters a class instead of a struct

media/audio/linux/alsa_output.h

Index: media/audio/linux/alsa_output.h
diff --git a/media/audio/linux/alsa_output.h b/media/audio/linux/alsa_output.h
index ee257ebb391ceb4a34d2a938bbc270c5c056f346..f1dbd3499cb796f3e515ce038b39049b9c2affed 100644
--- a/media/audio/linux/alsa_output.h
+++ b/media/audio/linux/alsa_output.h
@@ -123,8 +123,8 @@ class MEDIA_EXPORT AlsaPcmOutputStream : public AudioOutputStream {
   void ScheduleNextWrite(bool source_exhausted);
 
   // Utility functions for talking with the ALSA API.
-  static uint32 FramesToMicros(uint32 frames, uint32 sample_rate);
-  static uint32 FramesToMillis(uint32 frames, uint32 sample_rate);
+  static uint32 FramesToMicros(uint32 frames, uint32 samples_per_second);
+  static uint32 FramesToMillis(uint32 frames, uint32 samples_per_second);
   std::string FindDeviceForChannels(uint32 channels);
   snd_pcm_sframes_t GetAvailableFrames();
   snd_pcm_sframes_t GetCurrentDelay();
@@ -165,7 +165,7 @@ class MEDIA_EXPORT AlsaPcmOutputStream : public AudioOutputStream {
   const std::string requested_device_name_;
   const snd_pcm_format_t pcm_format_;
   const uint32 channels_;
-  const uint32 sample_rate_;
+  const uint32 samples_per_second_;
   const uint32 bytes_per_sample_;
   const uint32 bytes_per_frame_;