Make AudioParameters a class instead of a struct

content/browser/renderer_host/render_message_filter.cc

Index: content/browser/renderer_host/render_message_filter.cc
diff --git a/content/browser/renderer_host/render_message_filter.cc b/content/browser/renderer_host/render_message_filter.cc
index 646f94da384453ee4ad9571ff8cc0adc4a44f466..f6c9fb1003eecc17ea69bfb2473ef748f5a96e74 100644
--- a/content/browser/renderer_host/render_message_filter.cc
+++ b/content/browser/renderer_host/render_message_filter.cc
@@ -378,8 +378,8 @@ bool RenderMessageFilter::OnMessageReceived(const IPC::Message& message,
                         OnGetHardwareInputSampleRate)
     IPC_MESSAGE_HANDLER(ViewHostMsg_GetHardwareSampleRate,
                         OnGetHardwareSampleRate)
-    IPC_MESSAGE_HANDLER(ViewHostMsg_GetHardwareInputChannelCount,
-                        OnGetHardwareInputChannelCount)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_GetHardwareInputChannelLayout,
+                        OnGetHardwareInputChannelLayout)
     IPC_MESSAGE_HANDLER(ViewHostMsg_MediaLogEvent, OnMediaLogEvent)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
@@ -676,10 +676,11 @@ void RenderMessageFilter::OnGetHardwareSampleRate(double* sample_rate) {
   *sample_rate = media::GetAudioHardwareSampleRate();
 }
 
-void RenderMessageFilter::OnGetHardwareInputChannelCount(uint32* channels) {
+void RenderMessageFilter::OnGetHardwareInputChannelLayout(
+    ChannelLayout* layout) {
   // TODO(henrika): add support for all available input devices.
-  *channels = static_cast<uint32>(media::GetAudioInputHardwareChannelCount(
-      AudioManagerBase::kDefaultDeviceId));
+  *layout = media::GetAudioInputHardwareChannelLayout(
+      AudioManagerBase::kDefaultDeviceId);
 }
 
 void RenderMessageFilter::OnDownloadUrl(const IPC::Message& message,