Move all typecasting code to individual screens.

chrome/browser/chromeos/login/enrollment/auto_enrollment_check_screen.cc

 // 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.
 
 #include "chrome/browser/chromeos/login/enrollment/auto_enrollment_check_screen.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "chrome/browser/chromeos/login/screen_manager.h"
 #include "chrome/browser/chromeos/login/screens/screen_observer.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler.h"
 
 namespace chromeos {
 
+// static
+AutoEnrollmentCheckScreen* AutoEnrollmentCheckScreen::Get(
+    ScreenManager* manager) {
+  return static_cast<AutoEnrollmentCheckScreen*>(
+      manager->GetScreen(WizardController::kAutoEnrollmentCheckScreenName));
+}
+
 AutoEnrollmentCheckScreen::AutoEnrollmentCheckScreen(
     ScreenObserver* observer,
     AutoEnrollmentCheckScreenActor* actor)
     : WizardScreen(observer),
       actor_(actor),
       captive_portal_status_(
           NetworkPortalDetector::CAPTIVE_PORTAL_STATUS_UNKNOWN),
       auto_enrollment_state_(policy::AUTO_ENROLLMENT_STATE_IDLE) {
   if (actor_)
     actor_->SetDelegate(this);
@@ skipping 185 matching lines @@
 }
 
 void AutoEnrollmentCheckScreen::SignalCompletion() {
   NetworkPortalDetector::Get()->RemoveObserver(this);
   auto_enrollment_progress_subscription_.reset();
   get_screen_observer()->OnExit(
       ScreenObserver::ENTERPRISE_AUTO_ENROLLMENT_CHECK_COMPLETED);
 }
 
 }  // namespace chromeos