Move all typecasting code to individual screens.

chrome/browser/chromeos/login/screens/user_image_screen.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_CHROMEOS_LOGIN_SCREENS_USER_IMAGE_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_IMAGE_SCREEN_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/camera_presence_notifier.h"
+#include "chrome/browser/chromeos/login/screen_manager.h"

[ygorshenin1, 2014/09/03 13:30:22]

You dont' need inclusion of screen_manager.h here, as you already
forward-declared it. Move inclusion to the *.cc part.

 #include "chrome/browser/chromeos/login/screens/user_image_screen_actor.h"
 #include "chrome/browser/chromeos/login/screens/wizard_screen.h"
 #include "chrome/browser/chromeos/login/users/avatar/user_image_sync_observer.h"
 #include "chrome/browser/image_decoder.h"
 #include "components/user_manager/user.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
 namespace base {
 class Timer;
 class Value;
 };
 
 namespace policy {
 class PolicyChangeRegistrar;
 }
 
 namespace chromeos {
 
 class UserImageManager;
+class ScreenManager;
 
 class UserImageScreen: public WizardScreen,
                        public UserImageScreenActor::Delegate,
                        public ImageDecoder::Delegate,
                        public content::NotificationObserver,
                        public UserImageSyncObserver::Observer,
                        public CameraPresenceNotifier::Observer {
  public:
   UserImageScreen(ScreenObserver* screen_observer,
                   UserImageScreenActor* actor);
   virtual ~UserImageScreen();
 
+  static UserImageScreen* Get(ScreenManager* manager);
+
   // WizardScreen implementation:
   virtual void PrepareToShow() OVERRIDE;
   virtual void Show() OVERRIDE;
   virtual void Hide() OVERRIDE;
   virtual std::string GetName() const OVERRIDE;
 
   // UserImageScreenActor::Delegate implementation:
   virtual void OnScreenReady() OVERRIDE;
   virtual void OnPhotoTaken(const std::string& raw_data) OVERRIDE;
   virtual void OnImageSelected(const std::string& image_url,
@@ skipping 86 matching lines @@
 
   // True if user has explicitly selected some image.
   bool user_has_selected_image_;
 
   DISALLOW_COPY_AND_ASSIGN(UserImageScreen);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_IMAGE_SCREEN_H_