Eliminate build differences in nacl gated on nacl_standalone.

build/external_code.gypi

-# Copyright (c) 2009 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.
-
-{
-  'conditions': [
-    [ 'OS=="linux"', {
-      'target_defaults': {
-        'cflags!': [
-          '-Wall',
-          '-Werror',
-        ],
-      },
-    }],
-    [ 'OS=="win"', {
-      'target_defaults': {
-        'defines': [
-          '_CRT_SECURE_NO_DEPRECATE',
-          '_CRT_NONSTDC_NO_WARNINGS',
-          '_CRT_NONSTDC_NO_DEPRECATE',
-          '_SCL_SECURE_NO_DEPRECATE',
-        ],
-        'msvs_disabled_warnings': [4800],
-        'msvs_settings': {
-          'VCCLCompilerTool': {
-            'WarnAsError': 'false',
-            'Detect64BitPortabilityProblems': 'false',
-          },
-        },
-      },
-    }],
-    [ 'OS=="mac"', {
-      'target_defaults': {
-        'xcode_settings': {
-          'GCC_TREAT_WARNINGS_AS_ERRORS': 'NO',
-          'WARNING_CFLAGS!': ['-Wall'],
-        },
-      },
-    }],
-  ],
-}