components: Cleanup class/struct fwd declarations

components/user_manager/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 COMPONENTS_USER_MANAGER_USER_MANAGER_H_
 #define COMPONENTS_USER_MANAGER_USER_MANAGER_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager_export.h"
 #include "components/user_manager/user_type.h"
 
 class AccountId;
 class PrefService;
 
-namespace base {
-class DictionaryValue;
-}
-
 namespace chromeos {
-class LoginState;
 class ScopedUserManagerEnabler;
 }
 
-namespace cryptohome {
-class AsyncMethodCaller;
-}
-
 namespace user_manager {
 
 class RemoveUserDelegate;
 
 // Interface for UserManagerBase - that provides base implementation for
 // Chrome OS user management. Typical features:
 // * Get list of all know users (who have logged into this Chrome OS device)
 // * Keep track for logged in/LRU users, active user in multi-user session.
 // * Find/modify users, store user meta-data such as display name/email.
 class USER_MANAGER_EXPORT UserManager {
@@ skipping 340 matching lines @@
   static UserManager* GetForTesting();
 
   // Sets UserManager instance to the given |user_manager|.
   // Returns the previous value of the instance.
   static UserManager* SetForTesting(UserManager* user_manager);
 };
 
 }  // namespace user_manager
 
 #endif  // COMPONENTS_USER_MANAGER_USER_MANAGER_H_