Restructure the ipc_fuzzer directory.

tools/ipc_fuzzer/message_dump/message_dump.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'ipc_message_dump',
       'type': 'loadable_module',
       'dependencies': [
         '../message_lib/message_lib.gyp:ipc_message_lib',
       ],
       'sources': [
         'message_dump.cc',
       ],
       'include_dirs': [
         '../../..',
       ],
     },
   ],
 }