[cros] user_manager component - move UserManagerBase and UserManager

chrome/browser/chromeos/login/users/scoped_user_manager_enabler.h

+// Copyright 2014 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_LOGIN_USERS_SCOPED_USER_MANAGER_ENABLER_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_USERS_SCOPED_USER_MANAGER_ENABLER_H_
+
+#include "base/basictypes.h"
+
+namespace user_manager {
+class UserManager;
+}
+
+namespace chromeos {
+
+// Helper class for unit tests. Initializes the UserManager singleton to the
+// given |user_manager| and tears it down again on destruction. If the singleton
+// had already been initialized, its previous value is restored after tearing
+// down |user_manager|.
+class ScopedUserManagerEnabler {
+ public:
+  // Takes ownership of |user_manager|.
+  explicit ScopedUserManagerEnabler(user_manager::UserManager* user_manager);
+  ~ScopedUserManagerEnabler();
+
+ private:
+  user_manager::UserManager* previous_user_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedUserManagerEnabler);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USERS_SCOPED_USER_MANAGER_ENABLER_H_