Move all typecasting code to individual screens.

chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.h

 // Copyright 2014 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_SUPERVISED_SUPERVISED_USER_CREATION_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SUPERVISED_SUPERVISED_USER_CREATION_SCREEN_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "chrome/browser/chromeos/camera_presence_notifier.h"
 #include "chrome/browser/chromeos/login/screens/wizard_screen.h"
 #include "chrome/browser/chromeos/login/supervised/supervised_user_creation_controller.h"
 #include "chrome/browser/image_decoder.h"
 #include "chrome/browser/supervised_user/supervised_user_sync_service.h"
 #include "chrome/browser/ui/webui/chromeos/login/supervised_user_creation_screen_handler.h"
 #include "chromeos/network/portal_detector/network_portal_detector.h"
 #include "ui/gfx/image/image_skia.h"
 
 class Profile;
 
 namespace chromeos {
 
 class NetworkState;
+class ScreenManager;
 
 // Class that controls screen showing ui for supervised user creation.
 class SupervisedUserCreationScreen
     : public WizardScreen,
       public SupervisedUserCreationScreenHandler::Delegate,
       public SupervisedUserCreationController::StatusConsumer,
       public SupervisedUserSyncServiceObserver,
       public ImageDecoder::Delegate,
       public NetworkPortalDetector::Observer,
       public CameraPresenceNotifier::Observer {
  public:
   SupervisedUserCreationScreen(
       ScreenObserver* observer,
       SupervisedUserCreationScreenHandler* actor);
   virtual ~SupervisedUserCreationScreen();
 
+  static SupervisedUserCreationScreen* Get(ScreenManager* manager);
+
   // Makes screen to show message about inconsistency in manager login flow
   // (e.g. password change detected, invalid OAuth token, etc).
   // Called when manager user is successfully authenticated, so ui elements
   // should result in forced logout.
   void ShowManagerInconsistentStateErrorScreen();
 
   // Called when authentication fails for manager with provided password.
   // Displays wrong password message on manager selection screen.
   void OnManagerLoginFailure();
 
@@ skipping 89 matching lines @@
   bool apply_photo_after_decoding_;
   int selected_image_;
 
   DISALLOW_COPY_AND_ASSIGN(SupervisedUserCreationScreen);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SUPERVISED_SUPERVISED_USER_CREATION_SCREEN_H_