NaCl/GYP: remove references to prep_toolchain.

ppapi/ppapi_shared_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',
@@ skipping 13 matching lines @@
             'build_glibc': 0,
             'build_newlib': 0,
             'build_irt': 1,
             'build_pnacl_newlib': 0,
             'build_nonsfi_helper': 1,
           },
           'include_dirs': [
             '..',
           ],
           'dependencies': [
-            '../native_client/tools.gyp:prep_toolchain',
             '../base/base_nacl.gyp:base_nacl',
             '../base/base_nacl.gyp:base_nacl_nonsfi',
             '../gpu/command_buffer/command_buffer_nacl.gyp:gles2_utils_nacl',
             '../gpu/gpu_nacl.gyp:command_buffer_client_nacl',
             '../gpu/gpu_nacl.gyp:gles2_implementation_nacl',
             '../media/media_nacl.gyp:shared_memory_support_nacl',
             '../third_party/khronos/khronos.gyp:khronos_headers',
           ],
         },
       ],
     }],
   ],
 }