Do not define OS_CHROMEOS for untrusted NaCl code

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 2429 matching lines @@
       }],
       ['use_x11==1', {
         'defines': ['USE_X11=1'],
       }],
       ['use_clipboard_aurax11==1', {
         'defines': ['USE_CLIPBOARD_AURAX11=1'],
       }],
       ['enable_one_click_signin==1', {
         'defines': ['ENABLE_ONE_CLICK_SIGNIN'],
       }],
-      ['chromeos==1', {
-        'defines': ['OS_CHROMEOS=1'],
-      }],
       ['use_xi2_mt!=0 and use_x11==1', {
         'defines': ['USE_XI2_MT=<(use_xi2_mt)'],
       }],
       ['image_loader_extension==1', {
         'defines': ['IMAGE_LOADER_EXTENSION=1'],
       }],
       ['profiling==1', {
         'defines': ['ENABLE_PROFILING=1'],
       }],
       ['remoting==1', {
@@ skipping 315 matching lines @@
       }],
       ['>(nacl_untrusted_build)==1', {
         'defines': [
           'USE_OPENSSL=1',
           'USE_OPENSSL_CERTS=1',
         ],
       }],
       ['<(use_nss)==1 and >(nacl_untrusted_build)==0', {
         'defines': ['USE_NSS=1'],
       }],
+      ['<(chromeos)==1 and >(nacl_untrusted_build)==0', {
+        'defines': ['OS_CHROMEOS=1'],
+      }],
       ['enable_wexit_time_destructors==1', {
         'conditions': [
           [ 'clang==1', {
             'cflags': [
               '-Wexit-time-destructors',
             ],
             'xcode_settings': {
               'WARNING_CFLAGS': [
                 '-Wexit-time-destructors',
               ],
@@ skipping 2640 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }