Introduce NativeWebContentsModalDialogManagerDelegate interface

chrome/browser/ui/native_web_contents_modal_dialog_manager.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_NATIVE_WEB_CONTENTS_MODAL_DIALOG_MANAGER_H_
 #define CHROME_BROWSER_UI_NATIVE_WEB_CONTENTS_MODAL_DIALOG_MANAGER_H_
 
 #include "chrome/browser/ui/native_web_contents_modal_dialog.h"
 
+class WebContentsModalDialog;
+
+// Interface from NativeWebContentsModalDialogManager to
+// WebContentsModalDialogManager.
+class NativeWebContentsModalDialogManagerDelegate {
+ public:
+  NativeWebContentsModalDialogManagerDelegate() {}
+  virtual ~NativeWebContentsModalDialogManagerDelegate() {}
+
+  virtual void WillClose(WebContentsModalDialog* dialog) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NativeWebContentsModalDialogManagerDelegate);
+};
+
 // Provides an interface for platform-specific UI implementation for the web
 // contents modal dialog.
 class NativeWebContentsModalDialogManager {
  public:
   virtual ~NativeWebContentsModalDialogManager() {}
 
   // Starts management of the modal aspects of the dialog.  This function should
   // also register to be notified when the dialog is closing, so that it can
   // notify the manager.
   virtual void ManageDialog(NativeWebContentsModalDialog dialog) = 0;
 
   // Closes the web contents modal dialog.
   virtual void CloseDialog(NativeWebContentsModalDialog dialog) = 0;
 
  protected:
   NativeWebContentsModalDialogManager() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NativeWebContentsModalDialogManager);
 };
 
 #endif  // CHROME_BROWSER_UI_NATIVE_WEB_CONTENTS_MODAL_DIALOG_MANAGER_H_