Define os_posix in gyp files to get new Unix platforms added quickly

build/linux/system.gyp

 # Copyright (c) 2011 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': [
     ['sysroot!=""', {
       'variables': {
         'pkg-config': './pkg-config-wrapper "<(sysroot)"',
       },
     }, {
       'variables': {
         'pkg-config': 'pkg-config'
       },
     }],
-    [ 'OS=="linux" or OS=="freebsd" or OS=="openbsd"', {
+    [ 'os_posix==1 and OS!="mac"', {
       'variables': {
         # We use our own copy of libssl3, although we still need to link against
         # the rest of NSS.
         'use_system_ssl%': 0,
       },
-    }, {  # OS!="linux"
+    }, {
       'variables': {
         'use_system_ssl%': 1,
       },
     }],
   ],
 
 
   'targets': [
     {
       'target_name': 'gtk',
@@ skipping 356 matching lines @@
       ],
     },
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: