Make AudioParameters a class instead of a struct

content/common/media/audio_messages.h

Index: content/common/media/audio_messages.h
diff --git a/content/common/media/audio_messages.h b/content/common/media/audio_messages.h
index 03d73a9399b9c1d0b356e058d7004daaec492d75..bac2537eb13d9d2abb9ed7d3d0b1269ff5059287 100644
--- a/content/common/media/audio_messages.h
+++ b/content/common/media/audio_messages.h
@@ -9,6 +9,7 @@
 #include "base/shared_memory.h"
 #include "base/sync_socket.h"
 #include "content/common/content_export.h"
+#include "content/common/media/audio_param_traits.h"
 #include "content/common/media/audio_stream_state.h"
 #include "ipc/ipc_message_macros.h"
 #include "media/audio/audio_buffers_state.h"
@@ -19,23 +20,12 @@
 #define IPC_MESSAGE_START AudioMsgStart
 
 IPC_ENUM_TRAITS(AudioStreamState)
-IPC_ENUM_TRAITS(AudioParameters::Format)
-IPC_ENUM_TRAITS(ChannelLayout)
 
 IPC_STRUCT_TRAITS_BEGIN(AudioBuffersState)
   IPC_STRUCT_TRAITS_MEMBER(pending_bytes)
   IPC_STRUCT_TRAITS_MEMBER(hardware_delay_bytes)
 IPC_STRUCT_TRAITS_END()
 
-IPC_STRUCT_TRAITS_BEGIN(AudioParameters)
-  IPC_STRUCT_TRAITS_MEMBER(format)
-  IPC_STRUCT_TRAITS_MEMBER(channel_layout)
-  IPC_STRUCT_TRAITS_MEMBER(sample_rate)
-  IPC_STRUCT_TRAITS_MEMBER(bits_per_sample)
-  IPC_STRUCT_TRAITS_MEMBER(samples_per_packet)
-  IPC_STRUCT_TRAITS_MEMBER(channels)
-IPC_STRUCT_TRAITS_END()
-
 // Messages sent from the browser to the renderer.
 
 // Tell the renderer process that an audio stream has been created.