Move all typecasting code to individual screens.

chrome/browser/chromeos/login/screens/user_image_screen.cc

 // 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.
 
 #include "chrome/browser/chromeos/login/screens/user_image_screen.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 39 matching lines @@
 
 // Time histogram suffix for profile image download.
 const char kProfileDownloadReason[] = "OOBE";
 
 // Maximum amount of time to wait for the user image to sync.
 // The screen is shown iff sync failed or time limit exceeded.
 const int kSyncTimeoutSeconds = 10;
 
 }  // namespace
 
+// static
+UserImageScreen* UserImageScreen::Get(ScreenManager* manager) {
+  return static_cast<UserImageScreen*>(
+      manager->GetScreen(WizardController::kUserImageScreenName));
+}
+
 UserImageScreen::UserImageScreen(ScreenObserver* screen_observer,
                                  UserImageScreenActor* actor)
     : WizardScreen(screen_observer),
       actor_(actor),
       accept_photo_after_decoding_(false),
       selected_image_(user_manager::User::USER_IMAGE_INVALID),
       profile_picture_data_url_(url::kAboutBlankURL),
       profile_picture_absent_(false),
       is_screen_ready_(false),
       user_has_selected_image_(false) {
@@ skipping 278 matching lines @@
 
 void UserImageScreen::ExitScreen() {
   policy_registrar_.reset();
   sync_timer_.reset();
   if (UserImageSyncObserver* sync_observer = GetSyncObserver())
     sync_observer->RemoveObserver(this);
   get_screen_observer()->OnExit(ScreenObserver::USER_IMAGE_SELECTED);
 }
 
 }  // namespace chromeos