components: Cleanup class/struct fwd declarations

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 <map>
 #include <memory>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "components/signin/core/account_id/account_id.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
 #include "components/user_manager/user_manager_export.h"
 #include "components/user_manager/user_type.h"
 
-class PrefService;
 class PrefRegistrySimple;
 
 namespace base {
-class DictionaryValue;
 class ListValue;
 class TaskRunner;
 }
 
 namespace user_manager {
 
 class RemoveUserDelegate;
 
 // Base implementation of the UserManager interface.
 class USER_MANAGER_EXPORT UserManagerBase : public UserManager {
@@ skipping 345 matching lines @@
   scoped_refptr<base::TaskRunner> task_runner_;
 
   base::WeakPtrFactory<UserManagerBase> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UserManagerBase);
 };
 
 }  // namespace user_manager
 
 #endif  // COMPONENTS_USER_MANAGER_USER_MANAGER_BASE_H_