Removed unused mojo_nacl code and GYP targets.

mojo/nacl/mojo_syscall.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_NACL_MOJO_SYSCALL_H_
-#define MOJO_NACL_MOJO_SYSCALL_H_
-
-#include "mojo/public/c/system/types.h"
-
-// Injects a NaClDesc for Mojo support and sets a MojoHandle to be provided to
-// untrusted code as a "service provider" MojoHandle.  This provides the
-// implementation of the Mojo system API outside the NaCl sandbox and allows
-// untrusted code to communicate with Mojo interfaces outside the sandbox or in
-// other processes.
-void InjectMojo(struct NaClApp* nap, MojoHandle handle);
-
-// Injects a NaClDesc for Mojo support. This provides the implementation of the
-// Mojo system API outside the NaCl sandbox.
-// TODO(teravest): Remove this once it is no longer called.
-void InjectMojo(struct NaClApp* nap);
-
-// Injects a "disabled" NaClDesc for Mojo support. This is to make debugging
-// more straightforward in the case where Mojo is not enabled for NaCl plugins.
-void InjectDisabledMojo(struct NaClApp* nap);
-
-#endif // MOJO_NACL_MOJO_SYSCALL_H_