Use a uniform opaque type to represent web contents modal dialogs

chrome/browser/ui/web_contents_modal_dialog.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.
 
 #ifndef CHROME_BROWSER_UI_WEB_CONTENTS_MODAL_DIALOG_H_
 #define CHROME_BROWSER_UI_WEB_CONTENTS_MODAL_DIALOG_H_
 
-#include "build/build_config.h"
-#include "ui/gfx/native_widget_types.h"
+#include "chrome/browser/ui/native_web_contents_modal_dialog.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // WebContentsModalDialog
 //
 //  This interface represents a window that is constrained to a
 //  WebContentsView's bounds.
 //
 class WebContentsModalDialog {
  public:
   // Makes the web contents modal dialog visible. Only one web contents modal
   // dialog is shown at a time per tab.
   virtual void ShowWebContentsModalDialog() = 0;
 
   // Closes the web contents modal dialog.
   virtual void CloseWebContentsModalDialog() = 0;
 
   // Sets focus on the web contents modal dialog.
   virtual void FocusWebContentsModalDialog() = 0;
 
   // Runs a pulse animation for the web contents modal dialog.
   virtual void PulseWebContentsModalDialog() = 0;
 
-  // Returns the native window of the web contents modal dialog.
-  virtual gfx::NativeWindow GetNativeWindow() = 0;
+  // Returns the native representation of the web contents modal dialog.
+  virtual NativeWebContentsModalDialog GetNativeDialog() = 0;
 
  protected:
   virtual ~WebContentsModalDialog() {}
 };
 
 #endif  // CHROME_BROWSER_UI_WEB_CONTENTS_MODAL_DIALOG_H_