NaCl/GYP: remove references to prep_toolchain.

ipc/ipc_nacl.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/common_untrusted.gypi',
     'ipc.gypi',
   ],
   'conditions': [
     ['disable_nacl==0 and disable_nacl_untrusted==0', {
       'targets': [
         {
           'target_name': 'ipc_nacl',
           'type': 'none',
           'variables': {
             'ipc_target': 1,
             'nacl_untrusted_build': 1,
             'nlib_target': 'libipc_nacl.a',
             'build_glibc': 0,
             'build_newlib': 0,
             'build_irt': 1,
           },
           'dependencies': [
             '../base/base_nacl.gyp:base_nacl',
-            '../native_client/tools.gyp:prep_toolchain',
           ],
         },
         {
           'target_name': 'ipc_nacl_nonsfi',
           'type': 'none',
           'variables': {
             'ipc_target': 1,
             'nacl_untrusted_build': 1,
             'nlib_target': 'libipc_nacl_nonsfi.a',
             'build_glibc': 0,
             'build_newlib': 0,
             'build_irt': 0,
             'build_pnacl_newlib': 0,
             'build_nonsfi_helper': 1,
 
             # Use linux IPC channel implementation for nacl_helper_nonsfi,
             # instead of NaCl's IPC implementation (ipc_channel_nacl.cc),
             # because nacl_helper_nonsfi will be running directly on Linux.
             # ipc_channel_nacl.cc is excluded below.
             'sources': [
               'ipc_channel.cc',
               'ipc_channel_posix.cc',
             ],
           },
           'sources!': [
             'ipc_channel_nacl.cc',
           ],
           'dependencies': [
             '../base/base_nacl.gyp:base_nacl_nonsfi',
-            '../native_client/tools.gyp:prep_toolchain',
           ],
         },
       ],
     }],
   ],
 }