text: // Copyright (c) 2014 Marshall A. Greenblatt. Portions copyright (c) 2011
  // Google Inc. All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //    * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //    * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //    * Neither the name of Google Inc. nor the name Chromium Embedded
  // Framework nor the names of its contributors may be used to endorse
  // or promote products derived from this software without specific prior
  // written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #ifndef INCLUDE_BASE_CEF_CALLBACK_FORWARD_H_
  #define INCLUDE_BASE_CEF_CALLBACK_FORWARD_H_
  #pragma once
  
  #if defined(USING_CHROMIUM_INCLUDES)
  // When building CEF include the Chromium header directly.
  #include "base/callback_forward.h"
  #else  // !USING_CHROMIUM_INCLUDES
  // The following is substantially similar to the Chromium implementation.
  // If the Chromium implementation diverges the below implementation should be
  // updated to match.
  
  namespace base {
  
  template <typename Signature>
  class OnceCallback;
  
  template <typename Signature>
  class RepeatingCallback;
  
  // Syntactic sugar to make OnceClosure<void()> and RepeatingClosure<void()>
  // easier to declare since they will be used in a lot of APIs with delayed
  // execution.
  using OnceClosure = OnceCallback<void()>;
  using RepeatingClosure = RepeatingCallback<void()>;
  
  }  // namespace base
  
  #endif  // !!USING_CHROMIUM_INCLUDES
  
  #endif  // INCLUDE_BASE_CEF_CALLBACK_FORWARD_H_
  