user_manager component: Add UserManagerBase class.

chrome/browser/chromeos/login/users/user_manager.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_USER_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_USERS_USER_MANAGER_H_
 
 #include <string>
 
 #include "chrome/browser/chromeos/login/user_flow.h"
 #include "components/user_manager/user.h"
 
 class PrefRegistrySimple;
 
 namespace chromeos {
 
 class MultiProfileUserController;
 class RemoveUserDelegate;
 class UserImageManager;
 class SupervisedUserManager;
 
-// Base class for UserManagerImpl - provides a mechanism for discovering users
+// Interface for UserManagerBase - provides a mechanism for discovering users
 // who have logged into this Chrome OS device before and updating that list.
 class UserManager {
  public:
   // Interface that observers of UserManager must implement in order
   // to receive notification when local state preferences is changed
   class Observer {
    public:
     // Called when the local state preferences is changed.
     virtual void LocalStateChanged(UserManager* user_manager);
 
@@ skipping 94 matching lines @@
   // Returns a list of users who can unlock the device.
   // This list is based on policy and whether user is able to do unlock.
   // Policy:
   // * If user has primary-only policy then it is the only user in unlock users.
   // * Otherwise all users with unrestricted policy are added to this list.
   // All users that are unable to perform unlock are excluded from this list.
   virtual user_manager::UserList GetUnlockUsers() const = 0;
 
   // Returns the email of the owner user. Returns an empty string if there is
   // no owner for the device.
-  virtual const std::string& GetOwnerEmail() = 0;
+  virtual const std::string& GetOwnerEmail() const = 0;
 
   // Indicates that a user with the given |user_id| has just logged in. The
   // persistent list is updated accordingly if the user is not ephemeral.
   // |browser_restart| is true when reloading Chrome after crash to distinguish
   // from normal sign in flow.
   // |username_hash| is used to identify homedir mount point.
   virtual void UserLoggedIn(const std::string& user_id,
                             const std::string& username_hash,
                             bool browser_restart) = 0;
 
@@ skipping 196 matching lines @@
   ScopedTestUserManager();
   ~ScopedTestUserManager();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScopedTestUserManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USERS_USER_MANAGER_H_