MacViews: Unify web contents modal dialog types

components/web_modal/native_web_contents_modal_dialog.h

 // Copyright (c) 2013 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.
 
 #ifndef COMPONENTS_WEB_MODAL_NATIVE_WEB_CONTENTS_MODAL_DIALOG_H_
 #define COMPONENTS_WEB_MODAL_NATIVE_WEB_CONTENTS_MODAL_DIALOG_H_
 
 #include "ui/gfx/native_widget_types.h"
 
 namespace web_modal {
 
 // TODO(gbillock): rename this file
 
-#if defined(OS_MACOSX)
-// Use a void* since none of the gfx::Native* types are suitable for
-// representing the web contents modal dialog under Cocoa.
-typedef void* NativeWebContentsModalDialog;
-#else
-typedef gfx::NativeView NativeWebContentsModalDialog;
-#endif
-
-#if defined(OS_MACOSX)
-// Use a void* since none of the gfx::Native* types are suitable for
-// representing a popup window under Cocoa.
-typedef void* NativePopup;
-#else
-typedef gfx::NativeView NativePopup;
-#endif
+using NativeWebContentsModalDialog = gfx::NativeWindow;
+using NativePopup = gfx::NativeWindow;
 
 }  // namespace web_modal
 
 #endif  // COMPONENTS_WEB_MODAL_NATIVE_WEB_CONTENTS_MODAL_DIALOG_H_