replace platform conditions with os_posix and os_bsd where applicable

content/content_browser.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.
 
 {
   'dependencies': [
     '../crypto/crypto.gyp:crypto',
     '../net/net.gyp:net',
     '../net/net.gyp:http_server',
     '../ppapi/ppapi_internal.gyp:ppapi_proxy',
@@ skipping 697 matching lines @@
     }],
     ['chromeos==1', {
       'dependencies': [
         '../build/linux/system.gyp:dbus-glib',
       ],
       'sources!': [
         'browser/renderer_host/gtk_key_bindings_handler.cc',
         'browser/renderer_host/gtk_key_bindings_handler.h',
       ],
     }],
-    ['OS=="openbsd"', {
+    ['os_bsd==1', {
       'sources/': [
         ['exclude', '^browser/geolocation/wifi_data_provider_linux\\.cc$'],
       ],
     }],
     ['touchui==1', {
       'sources/': [
         ['exclude', '^browser/renderer_host/gtk_im_context_wrapper.cc'],
         ['exclude', '^browser/renderer_host/gtk_im_context_wrapper.h'],
         ['exclude', '^browser/renderer_host/render_widget_host_view_gtk.cc'],
         ['exclude', '^browser/renderer_host/render_widget_host_view_gtk.h'],
@@ skipping 69 matching lines @@
         'browser/renderer_host/java/java_bridge_dispatcher_host_manager.h',
         'browser/renderer_host/java/java_bridge_dispatcher_host.cc',
         'browser/renderer_host/java/java_bridge_dispatcher_host.h',
         'browser/renderer_host/java/java_method.cc',
         'browser/renderer_host/java/java_method.h',
       ],
     }],
   ],
 }