Readd base::UnwrapTraits to support rvalue-reference wrappers

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 25 matching lines @@
 #include "wtf/ThreadSafeRefCounted.h"
 #include "wtf/TypeTraits.h"
 #include "wtf/WeakPtr.h"
 #include <utility>
 
 namespace blink {
 template <typename T> class Member;
 template <typename T> class WeakMember;
 }
 
-namespace base {
-
-template <typename T>
-struct IsWeakReceiver<WTF::WeakPtr<T>> : std::true_type {};
-
-}
-
 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.
@@ skipping 102 matching lines @@
 template <typename T>
 struct ParamStorageTraits<PassRefPtr<T>> {
     typedef RefPtr<T> StorageType;
 };
 
 template <typename T>
 struct ParamStorageTraits<RefPtr<T>> {
     typedef RefPtr<T> StorageType;
 };
 
-template <typename T>
-T* Unwrap(const RefPtr<T>& wrapped)
-{
-    return wrapped.get();
-}
-
 template <typename> class RetainPtr;
 
 template <typename T>
 struct ParamStorageTraits<RetainPtr<T>> {
     typedef RetainPtr<T> StorageType;
 };
 
 template <typename T>
 struct ParamStorageTraits<PassedWrapper<T>> {
     typedef PassedWrapper<T> StorageType;
 };
 
-template <typename T>
-T Unwrap(const PassedWrapper<T>& wrapped)
-{
-    return wrapped.moveOut();
-}
-
 template <typename T, FunctionThreadAffinity threadAffinity>
 struct ParamStorageTraits<UnretainedWrapper<T, threadAffinity>> {
     typedef UnretainedWrapper<T, threadAffinity> StorageType;
 };
 
-template <typename T, FunctionThreadAffinity threadAffinity>
-T* Unwrap(const UnretainedWrapper<T, threadAffinity>& wrapped)
-{
-    return wrapped.value();
-}
-
 template<typename Signature, FunctionThreadAffinity threadAffinity = SameThreadAffinity>
 class Function;
 
 template<typename R, typename... Args, FunctionThreadAffinity threadAffinity>
 class Function<R(Args...), threadAffinity> {
     USING_FAST_MALLOC(Function);
     WTF_MAKE_NONCOPYABLE(Function);
 public:
     Function(base::Callback<R(Args...)> callback)
         : m_callback(std::move(callback)) { }
@@ skipping 34 matching lines @@
 std::unique_ptr<Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, SameThreadAffinity>> bind(FunctionType function, BoundParameters&&... boundParameters)
 {
     return bindInternal<SameThreadAffinity>(function, std::forward<BoundParameters>(boundParameters)...);
 }
 
 typedef Function<void(), SameThreadAffinity> Closure;
 typedef Function<void(), CrossThreadAffinity> CrossThreadClosure;
 
 } // namespace WTF
 
+namespace base {
+
+template <typename T>
+struct IsWeakReceiver<WTF::WeakPtr<T>> : std::true_type {};
+
+template <typename T>
+struct BindUnwrapTraits<WTF::RefPtr<T>> {
+    static T* Unwrap(const WTF::RefPtr<T>& wrapped)
+    {
+        return wrapped.get();
+    }
+};
+
+template <typename T>
+struct BindUnwrapTraits<WTF::PassedWrapper<T>> {
+    static T Unwrap(const WTF::PassedWrapper<T>& wrapped)
+    {
+        return wrapped.moveOut();
+    }
+};
+
+template <typename T, WTF::FunctionThreadAffinity threadAffinity>
+struct BindUnwrapTraits<WTF::UnretainedWrapper<T, threadAffinity>> {
+    static T* Unwrap(const WTF::UnretainedWrapper<T, threadAffinity>& wrapped)
+    {
+        return wrapped.value();
+    }
+};
+
+} // namespace base
+
 using WTF::passed;
 using WTF::unretained;
 using WTF::crossThreadUnretained;
 
 using WTF::Function;
 using WTF::CrossThreadClosure;
 
 #endif // WTF_Functional_h