Use a uniform opaque type to represent web contents modal dialogs

chrome/browser/ui/native_web_contents_modal_dialog.h

Index: chrome/browser/ui/native_web_contents_modal_dialog.h
diff --git a/chrome/browser/ui/native_web_contents_modal_dialog.h b/chrome/browser/ui/native_web_contents_modal_dialog.h
new file mode 100644
index 0000000000000000000000000000000000000000..3fb6445609022ba7c6de828edc44de6a745d30cf
--- /dev/null
+++ b/chrome/browser/ui/native_web_contents_modal_dialog.h
@@ -0,0 +1,18 @@
+// 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 CHROME_BROWSER_UI_NATIVE_WEB_CONTENTS_MODAL_DIALOG_H_
+#define CHROME_BROWSER_UI_NATIVE_WEB_CONTENTS_MODAL_DIALOG_H_
+
+#include "ui/gfx/native_widget_types.h"
+
+#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
+
+#endif  // CHROME_BROWSER_UI_NATIVE_WEB_CONTENTS_MODAL_DIALOG_H_