Factor out uses of the WebContentsModalDialog interface from platform-independent code

chrome/browser/ui/webui/constrained_web_dialog_ui.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_WEBUI_CONSTRAINED_WEB_DIALOG_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_CONSTRAINED_WEB_DIALOG_UI_H_
 
 #include "base/compiler_specific.h"
 #include "content/public/browser/web_ui_controller.h"
-
-class WebContentsModalDialog;
+#include "ui/gfx/native_widget_types.h"
 
 namespace content {
 class BrowserContext;
 class RenderViewHost;
 class WebContents;
 }
 
 namespace ui {
 class WebDialogDelegate;
 class WebDialogWebContentsDelegate;
 }
 
 class ConstrainedWebDialogDelegate {
  public:
   virtual const ui::WebDialogDelegate* GetWebDialogDelegate() const = 0;
   virtual ui::WebDialogDelegate* GetWebDialogDelegate() = 0;
 
   // Called when the dialog is being closed in response to a "DialogClose"
   // message from WebUI.
   virtual void OnDialogCloseFromWebUI() = 0;
 
   // If called, on dialog closure, the dialog will release its WebContents
   // instead of destroying it. After which point, the caller will own the
   // released WebContents.
   virtual void ReleaseWebContentsOnDialogClose() = 0;
 
-  // Returns the WebContentsModalDialog.
-  virtual WebContentsModalDialog* GetWindow() = 0;
-
   // Returns the WebContents owned by the constrained window.
   virtual content::WebContents* GetWebContents() = 0;
 
+  // Returns the NativeWindow used to display the dialog.
+  virtual gfx::NativeWindow GetNativeWindow() = 0;
+
  protected:
   virtual ~ConstrainedWebDialogDelegate() {}
 };
 
 // ConstrainedWebDialogUI is a facility to show HTML WebUI content
 // in a tab-modal constrained dialog.  It is implemented as an adapter
 // between an WebDialogUI object and a WebContentsModalDialog object.
 //
 // Since WebContentsModalDialog requires platform-specific delegate
 // implementations, this class is just a factory stub.
@@ skipping 36 matching lines @@
 //                use the default one. The dialog takes ownership of
 //                |tab_delegate|.
 // |overshadowed| is the tab being overshadowed by the dialog.
 ConstrainedWebDialogDelegate* CreateConstrainedWebDialog(
     content::BrowserContext* browser_context,
     ui::WebDialogDelegate* delegate,
     ui::WebDialogWebContentsDelegate* tab_delegate,
     content::WebContents* overshadowed);
 
 #endif  // CHROME_BROWSER_UI_WEBUI_CONSTRAINED_WEB_DIALOG_UI_H_