replace platform conditions with os_posix and os_bsd where applicable

net/net.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.
 
 {
   'variables': {
     'chromium_code': 1,
 
     'linux_link_kerberos%': 0,
     'conditions': [
@@ skipping 828 matching lines @@
               ['use_openssl==1', {
                 'dependencies': [
                   '../third_party/openssl/openssl.gyp:openssl',
                 ],
               },
               {  # else use_openssl==0, use NSS
                 'dependencies': [
                   '../build/linux/system.gyp:ssl',
                 ],
               }],
-              ['OS=="openbsd"', {
+              ['os_bsd==1', {
                 'sources!': [
                   'base/network_change_notifier_linux.cc',
                   'base/network_change_notifier_netlink_linux.cc',
                   'proxy/proxy_config_service_linux.cc',
                 ],
               },{
                 'dependencies': [
                   '../build/linux/system.gyp:libresolv',
                 ],
               }],
@@ skipping 823 matching lines @@
             'tools/dump_cache/url_to_filename_encoder.cc',
             'tools/dump_cache/url_to_filename_encoder.h',
             'tools/dump_cache/url_utilities.h',
             'tools/dump_cache/url_utilities.cc',
           ],
         },
       ],
     }],
   ],
 }