Make AudioParameters a class instead of a struct

media/audio/mac/audio_input_mac.cc

Index: media/audio/mac/audio_input_mac.cc
diff --git a/media/audio/mac/audio_input_mac.cc b/media/audio/mac/audio_input_mac.cc
index e886ddf9698d899363b33a4e3629094c3126f9c0..61ab281dadb22a18899607bd1cea9f4c0db9af1d 100644
--- a/media/audio/mac/audio_input_mac.cc
+++ b/media/audio/mac/audio_input_mac.cc
@@ -30,18 +30,18 @@ PCMQueueInAudioInputStream::PCMQueueInAudioInputStream(
   // A frame is one sample across all channels. In interleaved audio the per
   // frame fields identify the set of n |channels|. In uncompressed audio, a
   // packet is always one frame.
-  format_.mSampleRate = params.sample_rate;
+  format_.mSampleRate = params.sample_rate();
   format_.mFormatID = kAudioFormatLinearPCM;
   format_.mFormatFlags = kLinearPCMFormatFlagIsPacked |
                          kLinearPCMFormatFlagIsSignedInteger;
-  format_.mBitsPerChannel = params.bits_per_sample;
-  format_.mChannelsPerFrame = params.channels;
+  format_.mBitsPerChannel = params.bits_per_sample();
+  format_.mChannelsPerFrame = params.channels();
   format_.mFramesPerPacket = 1;
-  format_.mBytesPerPacket = (params.bits_per_sample * params.channels) / 8;
+  format_.mBytesPerPacket = (params.bits_per_sample() * params.channels()) / 8;
   format_.mBytesPerFrame = format_.mBytesPerPacket;
   format_.mReserved = 0;
 
-  buffer_size_bytes_ = params.GetPacketSize();
+  buffer_size_bytes_ = params.GetBytesPerBuffer();
 }
 
 PCMQueueInAudioInputStream::~PCMQueueInAudioInputStream() {