|  | // Copyright (c) 2011 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 BASE_CALLBACK_FORWARD_H_ | 
|  | #define BASE_CALLBACK_FORWARD_H_ | 
|  |  | 
|  | namespace base { | 
|  |  | 
|  | template <typename Signature> | 
|  | class OnceCallback; | 
|  |  | 
|  | template <typename Signature> | 
|  | class RepeatingCallback; | 
|  |  | 
|  | template <typename Signature> | 
|  | using Callback = RepeatingCallback<Signature>; | 
|  |  | 
|  | // Syntactic sugar to make Callback<void()> easier to declare since it | 
|  | // will be used in a lot of APIs with delayed execution. | 
|  | using OnceClosure = OnceCallback<void()>; | 
|  | using RepeatingClosure = RepeatingCallback<void()>; | 
|  | using Closure = Callback<void()>; | 
|  |  | 
|  | }  // namespace base | 
|  |  | 
|  | #endif  // BASE_CALLBACK_FORWARD_H_ |