Make the gyp files more cross-platform across the Unices

chrome/chrome_exe.gypi

 # 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.
 
 {
   'target_defaults': {
     'variables': {
       'chrome_exe_target': 0,
     },
     'target_conditions': [
@@ skipping 132 matching lines @@
       'target_name': 'chrome',
       'type': 'executable',
       'mac_bundle': 1,
       'msvs_guid': '7B219FAA-E360-43C8-B341-804A94EEFFAC',
       'variables': {
         'chrome_exe_target': 1,
         'use_system_xdg_utils%': 0,
         'disable_pie%': 0,
       },
       'conditions': [
-        ['OS=="linux" or OS=="freebsd" or OS=="openbsd"', {
+        ['os_posix == 1 and OS != "mac"', {
           'actions': [
             {
               'action_name': 'manpage',
               'conditions': [
                 [ 'branding == "Chrome"', {
                   'variables': {
                     'name': 'Google Chrome',
                     'filename': 'google-chrome',
                     'confdir': 'google-chrome',
                   },
@@ skipping 366 matching lines @@
           'configurations': {
             'Common_Base': {
               'msvs_target_platform': 'x64',
             },
           },
         },
       ],
     }],
   ],
 }