Move crossThreadBind() from platform/ to wtf/

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 43 matching lines @@
 namespace WTF {
 
 // Functional.h provides a very simple way to bind a function pointer and arguments together into a function object
 // that can be stored, copied and invoked, similar to how boost::bind and std::bind in C++11.
 
 // Thread Safety:
 //
 // WTF::bind() and WTF::Closure should be used for same-thread closures
 // only, i.e. the closures must be created, executed and destructed on
 // the same thread.
-// Use crossThreadBind() and CrossThreadClosure if the function/task is called
-// or destructed on a (potentially) different thread from the current thread.
+//
+// Use WTF::crossThreadBind() and WTF::CrossThreadClosure if the function/task
+// is called or destructed on a (potentially) different thread from the current
+// thread.
+// WTF::crossThreadBind() applies CrossThreadCopier to the arguments.
+// Example:
+//     void func1(int, const String&);
+//     f = crossThreadBind(func1, 42, str);
+// func1(42, str2) will be called when |f()| is executed,
+// where |str2| is a deep copy of |str| (created by str.isolatedCopy()).
+// Don't (if you pass the task across threads):
+//     bind(func1, 42, str);
+//     bind(func1, 42, str.isolatedCopy());
 
 // WTF::bind() and move semantics
 // ==============================
 //
 // For unbound parameters (arguments supplied later on the bound functor directly), there are two ways to pass movable
 // arguments:
 //
 //     1) Pass by rvalue reference.
 //
 //            void yourFunction(Argument&& argument) { ... }
@@ skipping 186 matching lines @@
     using UnboundRunType = base::MakeUnboundRunType<FunctionType, BoundParameters...>;
     return wrapUnique(new Function<UnboundRunType, threadAffinity>(base::Bind(function, typename ParamStorageTraits<typename std::decay<BoundParameters>::type>::StorageType(std::forward<BoundParameters>(boundParameters))...)));
 }
 
 template <typename FunctionType, typename... BoundParameters>
 std::unique_ptr<Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, SameThreadAffinity>> bind(FunctionType function, BoundParameters&&... boundParameters)
 {
     return bindInternal<SameThreadAffinity>(function, std::forward<BoundParameters>(boundParameters)...);
 }
 
+template <typename FunctionType, typename... BoundParameters>
+std::unique_ptr<Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, CrossThreadAffinity>> crossThreadBind(FunctionType function, BoundParameters&&... boundParameters)
+{
+    return bindInternal<CrossThreadAffinity>(function, CrossThreadCopier<typename std::decay<BoundParameters>::type>::copy(std::forward<BoundParameters>(boundParameters))...);
+}
+
 typedef Function<void(), SameThreadAffinity> Closure;
 typedef Function<void(), CrossThreadAffinity> CrossThreadClosure;
 
 } // namespace WTF
 
+using WTF::crossThreadBind;
+
 using WTF::passed;
 using WTF::unretained;
 using WTF::crossThreadUnretained;
 
 using WTF::Function;
 using WTF::CrossThreadClosure;
 
 #endif // WTF_Functional_h