Replace a WTF::Function conversion operator to be a 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 211 matching lines @@
     {
         DCHECK(m_threadChecker.CalledOnValidThread());
     }
 
     R operator()(Args... args)
     {
         DCHECK(m_threadChecker.CalledOnValidThread());
         return m_callback.Run(std::forward<Args>(args)...);
     }
 
-    explicit operator base::Callback<R(Args...)>()
+    friend base::Callback<R(Args...)> convertToBaseCallback(std::unique_ptr<Function> function)

[hiroshige, 2016/07/08 05:42:04]

Just checking: is this syntax allowed in the Blink style?

[tzik, 2016/07/08 05:53:50]

I think so. I found nothing that bans this in our style guide.

     {
-        return m_callback;
+        return std::move(function->m_callback);
     }
 
 private:
     using MaybeThreadChecker = typename std::conditional<
         threadAffinity == SameThreadAffinity,
         base::ThreadChecker,
         base::ThreadCheckerDoNothing>::type;
     MaybeThreadChecker m_threadChecker;
     base::Callback<R(Args...)> m_callback;
 };
@@ skipping 17 matching lines @@
 } // namespace WTF
 
 using WTF::passed;
 using WTF::unretained;
 using WTF::crossThreadUnretained;
 
 using WTF::Function;
 using WTF::CrossThreadClosure;
 
 #endif // WTF_Functional_h