Make AudioParameters a class instead of a struct

content/common/view_messages.h

 // 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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "content/common/content_export.h"
 #include "content/common/css_colors.h"
 #include "content/common/edit_command.h"
 #include "content/common/navigation_gesture.h"
 #include "content/common/view_message_enums.h"
 #include "content/public/common/common_param_traits.h"
 #include "content/public/common/context_menu_params.h"
 #include "content/public/common/file_chooser_params.h"
 #include "content/public/common/frame_navigate_params.h"
 #include "content/public/common/page_zoom.h"
 #include "content/public/common/referrer.h"
 #include "content/public/common/renderer_preferences.h"
 #include "content/public/common/selected_file_info.h"
 #include "content/public/common/stop_find_action.h"
 #include "content/public/common/webkit_param_traits.h"
 #include "content/public/common/window_container_type.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_platform_file.h"
+#include "media/base/channel_layout.h"
 #include "media/base/media_log_event.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCompositionUnderline.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFindOptions.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaPlayerAction.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPluginAction.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPopupType.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebScreenInfo.h"
 #include "ui/base/ime/text_input_type.h"
 #include "ui/base/javascript_message_type.h"
 #include "ui/base/range/range.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 #include "webkit/glue/webcookie.h"
 #include "webkit/glue/webmenuitem.h"
 #include "webkit/glue/webpreferences.h"
 #include "webkit/plugins/npapi/webplugin.h"
 
 #if defined(OS_MACOSX)
 #include "content/common/mac/font_descriptor.h"
 #endif
 
 #undef IPC_MESSAGE_EXPORT
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 
 #define IPC_MESSAGE_START ViewMsgStart
 
+IPC_ENUM_TRAITS(ChannelLayout)
 IPC_ENUM_TRAITS(CSSColors::CSSColorName)
 IPC_ENUM_TRAITS(NavigationGesture)
 IPC_ENUM_TRAITS(ViewMsg_Navigate_Type::Value)
 IPC_ENUM_TRAITS(WebKit::WebContextMenuData::MediaType)
 IPC_ENUM_TRAITS(WebKit::WebMediaPlayerAction::Type)
 IPC_ENUM_TRAITS(WebKit::WebPluginAction::Type)
 IPC_ENUM_TRAITS(WebKit::WebPopupType)
 IPC_ENUM_TRAITS(WebKit::WebReferrerPolicy)
 IPC_ENUM_TRAITS(WebKit::WebTextDirection)
 IPC_ENUM_TRAITS(WebMenuItem::Type)
@@ skipping 606 matching lines @@
 // Asks the browser for a unique routing ID.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GenerateRoutingID,
                             int /* routing_id */)
 
 // Asks the browser for the default audio hardware buffer-size.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareBufferSize,
                             uint32 /* buffer_size */)
 
 // Asks the browser for the default audio input hardware sample-rate.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareInputSampleRate,
-                            double /* sample_rate */)
+                            int /* sample_rate */)
 
 // Asks the browser for the default audio hardware sample-rate.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareSampleRate,
-                            double /* sample_rate */)
+                            int /* sample_rate */)
 
-// Asks the browser for the default number of audio input channels.
-IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareInputChannelCount,
-                            uint32 /* channels */)
+// Asks the browser for the default channel layout.
+IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareInputChannelLayout,
+                            ChannelLayout /* channel layout */)
 
 // Asks the browser for CPU usage of the renderer process in percents.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetCPUUsage,
                             int /* CPU usage in percents */)
 
 // Tells the renderer to create a new view.
 // This message is slightly different, the view it takes (via
 // ViewMsg_New_Params) is the view to create, the message itself is sent as a
 // non-view control message.
 IPC_MESSAGE_CONTROL1(ViewMsg_New,
@@ skipping 1263 matching lines @@
 // have a javascript send a native value (string, number, boolean) to the
 // listener in Cpp. (DomAutomationController)
 IPC_MESSAGE_ROUTED2(ViewHostMsg_DomOperationResponse,
                     std::string  /* json_string */,
                     int  /* automation_id */)
 
 // Enable or disable inverting of web content pixels, for users who prefer
 // white-on-black.
 IPC_MESSAGE_ROUTED1(ViewMsg_InvertWebContent,
                     bool /* invert */)