Make the fuchsia mojo/public repo the source of truth.

mojo/public/cpp/bindings/lib/message_internal.h

-// Copyright 2014 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_PUBLIC_CPP_BINDINGS_LIB_MESSAGE_INTERNAL_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_LIB_MESSAGE_INTERNAL_H_
-
-#include "mojo/public/cpp/bindings/lib/bindings_internal.h"
-
-namespace mojo {
-namespace internal {
-
-#pragma pack(push, 1)
-
-enum { kMessageExpectsResponse = 1 << 0, kMessageIsResponse = 1 << 1 };
-
-struct MessageHeader : internal::StructHeader {
-  uint32_t name;
-  uint32_t flags;
-};
-static_assert(sizeof(MessageHeader) == 16, "Bad sizeof(MessageHeader)");
-
-struct MessageHeaderWithRequestID : MessageHeader {
-  uint64_t request_id;
-};
-static_assert(sizeof(MessageHeaderWithRequestID) == 24,
-              "Bad sizeof(MessageHeaderWithRequestID)");
-
-struct MessageData {
-  MessageHeader header;
-};
-
-static_assert(sizeof(MessageData) == sizeof(MessageHeader),
-              "Bad sizeof(MessageData)");
-
-#pragma pack(pop)
-
-}  // namespace internal
-}  // namespace mojo
-
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_MESSAGE_INTERNAL_H_