Remove NOTIFICATION_SYSTEM_SETTING_CHANGED, switch CrosSettings to base::CallbackRegistry.

chrome/browser/chromeos/login/login_screen_policy_browsertest.cc

 // Copyright 2013 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/command_line.h"
-#include "chrome/browser/chrome_notification_types.h"
+#include "base/memory/ref_counted.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 #include "chrome/browser/chromeos/policy/device_policy_cros_browser_test.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/settings/cros_settings_names.h"
 #include "chrome/browser/policy/proto/chromeos/chrome_device_policy.pb.h"
 #include "chrome/common/chrome_switches.h"
 #include "chromeos/chromeos_switches.h"
-#include "content/public/browser/notification_service.h"
-#include "content/public/test/mock_notification_observer.h"
 #include "content/public/test/test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace em = enterprise_management;
 
 namespace chromeos {
 
 class LoginScreenPolicyTest : public policy::DevicePolicyCrosBrowserTest {
   virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE {
     command_line->AppendSwitch(switches::kLoginManager);
     command_line->AppendSwitch(::switches::kEnableManagedUsers);
   }
 
   virtual void SetUpInProcessBrowserTestFixture() OVERRIDE {
     InstallOwnerKey();
     MarkAsEnterpriseOwned();
     DevicePolicyCrosBrowserTest::SetUpInProcessBrowserTestFixture();
   }
 };
 
 IN_PROC_BROWSER_TEST_F(LoginScreenPolicyTest, DisableSupervisedUsers) {
   EXPECT_FALSE(chromeos::UserManager::Get()->AreLocallyManagedUsersAllowed());
 
-  content::WindowedNotificationObserver windowed_observer(
-       chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED,
-       content::NotificationService::AllSources());
-  chromeos::CrosSettings::Get()->AddSettingsObserver(
-      chromeos::kAccountsPrefSupervisedUsersEnabled, &windowed_observer);
+  scoped_refptr<content::MessageLoopRunner> runner(
+      new content::MessageLoopRunner);
+  scoped_ptr<CrosSettings::ObserverSubscription> subscription(
+      chromeos::CrosSettings::Get()->AddSettingsObserver(
+          chromeos::kAccountsPrefSupervisedUsersEnabled,
+          runner->QuitClosure()));
+
   em::ChromeDeviceSettingsProto& proto(device_policy()->payload());
   proto.mutable_supervised_users_settings()->set_supervised_users_enabled(true);
   RefreshDevicePolicy();
-  windowed_observer.Wait();
+
+  runner->Run();
 
   EXPECT_TRUE(chromeos::UserManager::Get()->AreLocallyManagedUsersAllowed());
-
-  chromeos::CrosSettings::Get()->RemoveSettingsObserver(
-      chromeos::kAccountsPrefSupervisedUsersEnabled, &windowed_observer);
 }
 
 }  // namespace chromeos