Rework the way Widget::Init works:

chrome/browser/chromeos/login/screen_locker.h

 // Copyright (c) 2011 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_CHROMEOS_LOGIN_SCREEN_LOCKER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREEN_LOCKER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 150 matching lines @@
   // Starts screen saver.
   void StartScreenSaver();
 
   // Overridden from AcceleratorTarget:
   virtual bool AcceleratorPressed(const views::Accelerator& accelerator);
 
   // Event handler for client-event.
   CHROMEGTK_CALLBACK_1(ScreenLocker, void, OnClientEvent, GdkEventClient*);
 
   // The screen locker window.
-  views::WidgetGtk* lock_window_;
+  views::Widget* lock_window_;
 
-  // TYPE_CHILD widget to grab the keyboard/mouse input.
-  views::WidgetGtk* lock_widget_;
+  // Child widget to grab the keyboard/mouse input.
+  views::Widget* lock_widget_;
 
   // A view that accepts password.
   ScreenLockView* screen_lock_view_;
 
   // A view that can display html page as background.
   BackgroundView* background_view_;
 
   // View used to present CAPTCHA challenge input.
   CaptchaView* captcha_view_;
 
@@ skipping 57 matching lines @@
   base::Time start_time_;
   // The time when the authentication is started.
   base::Time authentication_start_time_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenLocker);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREEN_LOCKER_H_