text: /*
   * Copyright (C) 2013 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:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. 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.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 WTF_WeakPtr_h
  #define WTF_WeakPtr_h
  
  #include "base/memory/weak_ptr.h"
  #include "wtf/Noncopyable.h"
  
  namespace WTF {
  
  template <typename T>
  using WeakPtr = base::WeakPtr<T>;
  
  template <typename T>
  class WeakPtrFactory {
    WTF_MAKE_NONCOPYABLE(WeakPtrFactory<T>);
    USING_FAST_MALLOC(WeakPtrFactory);
  
   public:
    explicit WeakPtrFactory(T* ptr) : m_factory(ptr) {}
  
    WeakPtr<T> createWeakPtr() { return m_factory.GetWeakPtr(); }
  
    void revokeAll() { m_factory.InvalidateWeakPtrs(); }
  
    bool hasWeakPtrs() const { return m_factory.HasWeakPtrs(); }
  
   private:
    base::WeakPtrFactory<T> m_factory;
  };
  
  }  // namespace WTF
  
  using WTF::WeakPtr;
  using WTF::WeakPtrFactory;
  
  #endif
  