Groom user manager's code.

components/user_manager/user_manager_base.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 COMPONENTS_USER_MANAGER_USER_MANAGER_BASE_H_
 #define COMPONENTS_USER_MANAGER_USER_MANAGER_BASE_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 261 matching lines @@
   // Returns a list of users who have logged into this device previously.
   // Same as GetUsers but used if you need to modify User from that list.
   UserList& GetUsersAndModify();
 
   // Returns the user with the given email address if found in the persistent
   // list. Returns |NULL| otherwise.
   const User* FindUserInList(const std::string& user_id) const;
 
   // Returns |true| if user with the given id is found in the persistent list.
   // Returns |false| otherwise. Does not trigger user loading.
-  const bool UserExistsInList(const std::string& user_id) const;
+  bool UserExistsInList(const std::string& user_id) const;
 
   // Same as FindUserInList but returns non-const pointer to User object.
   User* FindUserInListAndModify(const std::string& user_id);
 
   // Reads user's oauth token status from local state preferences.
   User::OAuthTokenStatus LoadUserOAuthStatus(const std::string& user_id) const;
 
   // Read a flag indicating whether online authentication against GAIA should
   // be enforced during the user's next sign-in from local state preferences.
   bool LoadForceOnlineSignin(const std::string& user_id) const;
@@ skipping 90 matching lines @@
   scoped_refptr<base::TaskRunner> blocking_task_runner_;
 
   base::WeakPtrFactory<UserManagerBase> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UserManagerBase);
 };
 
 }  // namespace user_manager
 
 #endif  // COMPONENTS_USER_MANAGER_USER_MANAGER_BASE_H_