Move all typecasting code to individual screens.

chrome/browser/chromeos/login/screens/network_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/network_screen.h"
 
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/chromeos/login/help_app_launcher.h"
 #include "chrome/browser/chromeos/login/helper.h"
 #include "chrome/browser/chromeos/login/login_utils.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 "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
 #include "chromeos/network/network_handler.h"
 #include "chromeos/network/network_state_handler.h"
 #include "ui/base/l10n/l10n_util.h"
 
 namespace {
 
 // Time in seconds for connection timeout.
 const int kConnectionTimeoutSec = 40;
 
 }  // namespace
 
 namespace chromeos {
 
 ///////////////////////////////////////////////////////////////////////////////
 // NetworkScreen, public:
 
+// static
+NetworkScreen* NetworkScreen::Get(ScreenManager* manager) {
+  return static_cast<NetworkScreen*>(
+      manager->GetScreen(WizardController::kNetworkScreenName));
+}
+
 NetworkScreen::NetworkScreen(ScreenObserver* screen_observer,
                              NetworkScreenActor* actor)
     : WizardScreen(screen_observer),
       is_network_subscribed_(false),
       continue_pressed_(false),
       actor_(actor),
       network_state_helper_(new login::NetworkStateHelper) {
   DCHECK(actor_);
   if (actor_)
     actor_->SetDelegate(this);
@@ skipping 153 matching lines @@
   }
 
   network_id_ = network_id;
   if (actor_) {
     actor_->ShowConnectingStatus(continue_pressed_, network_id_);
     actor_->EnableContinue(false);
   }
 }
 
 }  // namespace chromeos