cros: Use ScreenManager as a component instead of deriving WizardController from it

chrome/browser/chromeos/login/enterprise_enrollment_browsertest.cc

 // Copyright (c) 2015 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/macros.h"
 #include "chrome/browser/chromeos/login/enrollment/enrollment_screen.h"
 #include "chrome/browser/chromeos/login/enrollment/enterprise_enrollment_helper.h"
 #include "chrome/browser/chromeos/login/enrollment/enterprise_enrollment_helper_impl.h"
 #include "chrome/browser/chromeos/login/enrollment/enterprise_enrollment_helper_mock.h"
 #include "chrome/browser/chromeos/login/login_manager_test.h"
@@ skipping 183 matching lines @@
     ASSERT_TRUE(host != nullptr);
     host->StartWizard(OobeScreen::SCREEN_OOBE_ENROLLMENT);
     OobeScreenWaiter(OobeScreen::SCREEN_OOBE_ENROLLMENT).Wait();
     ASSERT_TRUE(enrollment_screen() != nullptr);
     ASSERT_TRUE(WizardController::default_controller() != nullptr);
     ASSERT_FALSE(StartupUtils::IsOobeCompleted());
   }
 
   // Helper method to return the current EnrollmentScreen instance.
   EnrollmentScreen* enrollment_screen() {
-    return EnrollmentScreen::Get(WizardController::default_controller());
+    return EnrollmentScreen::Get(
+        WizardController::default_controller()->screen_manager());
   }
 
  private:
   static std::vector<OnSetupEnrollmentHelper> enrollment_setup_functions_;
 
   DISALLOW_COPY_AND_ASSIGN(EnterpriseEnrollmentTest);
 };
 
 std::vector<EnterpriseEnrollmentTest::OnSetupEnrollmentHelper>
     EnterpriseEnrollmentTest::enrollment_setup_functions_;
@@ skipping 129 matching lines @@
   EXPECT_TRUE(IsStepDisplayed("ad-join"));
   js_checker().ExpectFalse(std::string(kAdMachineNameInput) + ".isInvalid");
   js_checker().ExpectTrue(std::string(kAdUsernameInput) + ".isInvalid");
   js_checker().ExpectFalse(std::string(kAdPasswordInput) + ".isInvalid");
 
   // We have to remove the enrollment_helper before the dtor gets called.
   enrollment_screen()->enrollment_helper_.reset();
 }
 
 }  // namespace chromeos