Make AudioParameters a class instead of a struct

content/renderer/media/audio_hardware.cc

 // 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.
 
 #include "content/renderer/media/audio_hardware.h"
 
 #include "base/logging.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/render_thread_impl.h"
 
-static double output_sample_rate = 0.0;
-static double input_sample_rate = 0.0;
+static int output_sample_rate = 0;
+static int input_sample_rate = 0;
 static size_t output_buffer_size = 0;
-static uint32 input_channel_count = 0;
+static ChannelLayout input_channel_layout = CHANNEL_LAYOUT_NONE;
 
 namespace audio_hardware {
 
-double GetOutputSampleRate() {
+int GetOutputSampleRate() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
   if (!output_sample_rate) {
     RenderThreadImpl::current()->Send(
         new ViewHostMsg_GetHardwareSampleRate(&output_sample_rate));
   }
   return output_sample_rate;
 }
 
-double GetInputSampleRate() {
+int GetInputSampleRate() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
   if (!input_sample_rate) {
     RenderThreadImpl::current()->Send(
         new ViewHostMsg_GetHardwareInputSampleRate(&input_sample_rate));
   }
   return input_sample_rate;
 }
 
 size_t GetOutputBufferSize() {
@@ skipping 32 matching lines @@
   // |kMillisecondsPerHardwarePacket| worth of audio data.
   size_t samples = kMinSamplesPerHardwarePacket;
   while (samples <= kMaxSamplesPerHardwarePacket &&
          samples * base::Time::kMillisecondsPerSecond <
          sample_rate * kMillisecondsPerHardwarePacket) {
     samples *= 2;
   }
   return samples;
 }
 
-uint32 GetInputChannelCount() {
+ChannelLayout GetInputChannelLayout() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
-  if (!input_channel_count) {
-    uint32 channels = 0;
+  if (input_channel_layout == CHANNEL_LAYOUT_NONE) {
+    ChannelLayout layout = CHANNEL_LAYOUT_NONE;
     RenderThreadImpl::current()->Send(
-        new ViewHostMsg_GetHardwareInputChannelCount(&channels));
-    input_channel_count = channels;
+        new ViewHostMsg_GetHardwareInputChannelLayout(&layout));
+    input_channel_layout = layout;
   }
 
-  return input_channel_count;
+  return input_channel_layout;
 }
 
 void ResetCache() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
   output_sample_rate = 0.0;
   input_sample_rate = 0.0;
   output_buffer_size = 0;
-  input_channel_count = 0;
+  input_channel_layout = CHANNEL_LAYOUT_NONE;
 }
 
 }  // namespace audio_hardware