Make Function's constructor and bindInternal() private

third_party/WebKit/Source/wtf/Functional.h

Index: third_party/WebKit/Source/wtf/Functional.h
diff --git a/third_party/WebKit/Source/wtf/Functional.h b/third_party/WebKit/Source/wtf/Functional.h
index bdcff7c12602e8cfd6f35a9fb937b235663cc1e4..d4f6c45f6ac7dbdd26645207f2bdde2cbbf36344 100644
--- a/third_party/WebKit/Source/wtf/Functional.h
+++ b/third_party/WebKit/Source/wtf/Functional.h
@@ -239,9 +239,6 @@ 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)) { }
-
     ~Function()
     {
         DCHECK(m_threadChecker.CalledOnValidThread());
@@ -259,6 +256,22 @@ public:
     }
 
 private:
+    Function(base::Callback<R(Args...)> callback)
+        : m_callback(std::move(callback)) { }
+
+    template <typename FunctionType, typename... BoundParameters>
+    static std::unique_ptr<Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, threadAffinity>> bindInternal(FunctionType function, BoundParameters&&... boundParameters)
+    {
+        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>
+    friend std::unique_ptr<Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, SameThreadAffinity>> bind(FunctionType, BoundParameters&&...);
+
+    template <typename FunctionType, typename... BoundParameters>
+    friend std::unique_ptr<Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, CrossThreadAffinity>> crossThreadBind(FunctionType, BoundParameters&&...);
+
     using MaybeThreadChecker = typename std::conditional<
         threadAffinity == SameThreadAffinity,
         base::ThreadChecker,
@@ -267,23 +280,16 @@ private:
     base::Callback<R(Args...)> m_callback;
 };
 
-template <FunctionThreadAffinity threadAffinity, typename FunctionType, typename... BoundParameters>
-std::unique_ptr<Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, threadAffinity>> bindInternal(FunctionType function, BoundParameters&&... boundParameters)
-{
-    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)...);
+    return Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, SameThreadAffinity>::bindInternal(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))...);
+    return Function<base::MakeUnboundRunType<FunctionType, BoundParameters...>, CrossThreadAffinity>::bindInternal(function, CrossThreadCopier<typename std::decay<BoundParameters>::type>::copy(std::forward<BoundParameters>(boundParameters))...);
 }
 
 typedef Function<void(), SameThreadAffinity> Closure;