Move all typecasting code to individual screens.

chrome/browser/chromeos/login/screens/network_screen_browsertest.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 "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/login/helper.h"
 #include "chrome/browser/chromeos/login/screens/mock_screen_observer.h"
 #include "chrome/browser/chromeos/login/screens/network_screen.h"
 #include "chrome/browser/chromeos/login/screens/wizard_screen.h"
 #include "chrome/browser/chromeos/login/test/wizard_in_process_browser_test.h"
@@ skipping 45 matching lines @@
     fake_session_manager_client_ = new FakeSessionManagerClient;
     DBusThreadManager::GetSetterForTesting()->SetSessionManagerClient(
         scoped_ptr<SessionManagerClient>(fake_session_manager_client_));
   }
 
   virtual void SetUpOnMainThread() OVERRIDE {
     WizardInProcessBrowserTest::SetUpOnMainThread();
     mock_screen_observer_.reset(new MockScreenObserver());
     ASSERT_TRUE(WizardController::default_controller() != NULL);
     network_screen_ =
-        WizardController::default_controller()->GetNetworkScreen();
+        NetworkScreen::Get(WizardController::default_controller());
     ASSERT_TRUE(network_screen_ != NULL);
     ASSERT_EQ(WizardController::default_controller()->current_screen(),
               network_screen_);
     network_screen_->screen_observer_ = mock_screen_observer_.get();
     ASSERT_TRUE(network_screen_->actor() != NULL);
 
     mock_network_state_helper_ = new login::MockNetworkStateHelper;
     SetDefaultNetworkStateHelperExpectations();
     network_screen_->SetNetworkStateHelperForTest(mock_network_state_helper_);
   }
@@ skipping 65 matching lines @@
   // EXPECT_FALSE(actor_->IsConnecting());
   network_screen_->OnConnectionTimeout();
 
   // Close infobubble with error message - it makes the test stable.
   // EXPECT_FALSE(actor_->IsContinueEnabled());
   // EXPECT_FALSE(actor_->IsConnecting());
   // actor_->ClearErrors();
 }
 
 }  // namespace chromeos