Move ScopedIPCSupport into its own build rule.

tools/ipc_fuzzer/message_replay/message_replay.gyp

 # Copyright 2013 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_fuzzer_replay',
       'type': 'executable',
       'dependencies': [
         '../message_lib/message_lib.gyp:ipc_message_lib',
-        '../../../ipc/mojo/ipc_mojo.gyp:ipc_mojo'
+        '../../../ipc/mojo/ipc_mojo.gyp:ipc_mojo',
+        '../../../ipc/mojo/ipc_mojo.gyp:ipc_mojo_support'
       ],
       'sources': [
         'replay.cc',
         'replay_process.cc',
         'replay_process.h',
       ],
       'include_dirs': [
         '../../..',
       ],
       'defines': [
         'USE_CUPS',
       ],
     },
   ],
 }