EDK: Move ref counting classes to mojo/edk/util.

mojo/edk/system/ref_ptr_internal.h

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef MOJO_EDK_SYSTEM_REF_PTR_INTERNAL_H_
-#define MOJO_EDK_SYSTEM_REF_PTR_INTERNAL_H_
-
-#include <utility>
-
-#include "mojo/public/cpp/system/macros.h"
-
-namespace mojo {
-namespace system {
-
-template <typename T>
-class RefPtr;
-
-template <typename T>
-RefPtr<T> AdoptRef(T* ptr);
-
-namespace internal {
-
-// This is a wrapper class that can be friended for a particular |T|, if you
-// want to make |T|'s constructor private, but still use |MakeRefCounted()|
-// (below). (You can't friend partial specializations.) See |MakeRefCounted()|
-// and |FRIEND_MAKE_REF_COUNTED()|.
-template <typename T>
-class MakeRefCountedHelper {
- public:
-  template <typename... Args>
-  static RefPtr<T> MakeRefCounted(Args&&... args) {
-    return AdoptRef<T>(new T(std::forward<Args>(args)...));
-  }
-};
-
-}  // namespace internal
-}  // namespace system
-}  // namespace mojo
-
-#endif  // MOJO_EDK_SYSTEM_REF_PTR_INTERNAL_H_