Add mojo structs for ScopedFD and ScopedHandle.

mojo/common/invalid_typemapped_type.h

+// Copyright 2016 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_COMMON_INVALID_TYPEMAPPED_TYPE_H_
+#define MOJO_COMMON_INVALID_TYPEMAPPED_TYPE_H_
+
+namespace mojo {
+namespace common {
+
+struct InvalidTypemappedType {
+  InvalidTypemappedType() = default;
+
+  InvalidTypemappedType(InvalidTypemappedType&& other) = default;
+  InvalidTypemappedType& operator=(InvalidTypemappedType&& other) = default;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(InvalidTypemappedType);
+};
+
+}  // namespace common
+}  // namespace mojo
+
+#endif  // MOJO_COMMON_INVALID_TYPEMAPPED_TYPE_H_