Move all typecasting code to individual screens.

chrome/browser/chromeos/login/enrollment/enrollment_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/enrollment/enrollment_screen.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 11 matching lines @@
 #include "chromeos/dbus/cryptohome_client.h"
 #include "chromeos/dbus/dbus_method_call_status.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "google_apis/gaia/gaia_auth_util.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 #include "policy/proto/device_management_backend.pb.h"
 
 namespace chromeos {
 
+// static
+EnrollmentScreen* EnrollmentScreen::Get(ScreenManager* manager) {
+  return static_cast<EnrollmentScreen*>(
+      manager->GetScreen(WizardController::kEnrollmentScreenName));
+}
+
 EnrollmentScreen::EnrollmentScreen(
     ScreenObserver* observer,
     EnrollmentScreenActor* actor)
     : WizardScreen(observer),
       actor_(actor),
       enrollment_mode_(EnrollmentScreenActor::ENROLLMENT_MODE_MANUAL),
       enrollment_failed_once_(false),
       remora_token_sent_(false),
       lockbox_init_duration_(0),
       weak_ptr_factory_(this) {
@@ skipping 310 matching lines @@
     sample = policy::kMetricEnrollmentAutoFailed;
   UMA(sample);
 }
 
 void EnrollmentScreen::ShowSigninScreen() {
   actor_->Show();
   actor_->ShowSigninScreen();
 }
 
 }  // namespace chromeos