Revert of Implement IPC::ParamTraits<mojo::MessagePipeHandle>

ipc/mojo/ipc_mojo_param_traits.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 IPC_MOJO_IPC_MOJO_PARAM_TRAITS_H_
-#define IPC_MOJO_IPC_MOJO_PARAM_TRAITS_H_
-
-#include <string>
-
-#include "ipc/ipc_export.h"
-#include "ipc/ipc_param_traits.h"
-#include "third_party/mojo/src/mojo/public/cpp/system/message_pipe.h"
-
-class PickleIterator;
-
-namespace IPC {
-
-class Message;
-
-template <>
-struct IPC_MOJO_EXPORT ParamTraits<mojo::MessagePipeHandle> {
-  typedef mojo::MessagePipeHandle param_type;
-  static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, PickleIterator* iter, param_type* r);
-  static void Log(const param_type& p, std::string* l);
-};
-
-}  // namespace IPC
-
-#endif  // IPC_MOJO_IPC_MOJO_PARAM_TRAITS_H_