Expose base::Callback::IsCancelled via WTF::Function

third_party/WebKit/Source/wtf/Functional.h

 /*
  * Copyright (C) 2011 Apple 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
@@ skipping 186 matching lines @@
     {
         DCHECK(m_threadChecker.CalledOnValidThread());
     }
 
     R operator()(Args... args)
     {
         DCHECK(m_threadChecker.CalledOnValidThread());
         return m_callback.Run(std::forward<Args>(args)...);
     }
 
+    bool isCancelled() const
+    {
+        return m_callback.IsCancelled();
+    }
+
     friend base::Callback<R(Args...)> convertToBaseCallback(std::unique_ptr<Function> function)
     {
         return std::move(function->m_callback);
     }
 
 private:
     using MaybeThreadChecker = typename std::conditional<
         threadAffinity == SameThreadAffinity,
         base::ThreadChecker,
         base::ThreadCheckerDoNothing>::type;
@@ skipping 51 matching lines @@
 } // namespace base
 
 using WTF::passed;
 using WTF::unretained;
 using WTF::crossThreadUnretained;
 
 using WTF::Function;
 using WTF::CrossThreadClosure;
 
 #endif // WTF_Functional_h