[net/dns] Isolate DnsConfigWatcher from DnsConfigService.

net/net.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
 
     'linux_link_kerberos%': 0,
     'conditions': [
@@ skipping 346 matching lines @@
         'disk_cache/trace.cc',
         'disk_cache/trace.h',
         'dns/dns_client.cc',
         'dns/dns_client.h',
         'dns/dns_config_service.cc',
         'dns/dns_config_service.h',
         'dns/dns_config_service_posix.cc',
         'dns/dns_config_service_posix.h',
         'dns/dns_config_service_win.cc',
         'dns/dns_config_service_win.h',
+        'dns/dns_config_watcher.h',
+        'dns/dns_config_watcher_posix.cc',
+        'dns/dns_config_watcher_win.cc',
         'dns/dns_hosts.cc',
         'dns/dns_hosts.h',
         'dns/dns_protocol.h',
         'dns/dns_query.cc',
         'dns/dns_query.h',
         'dns/dns_response.cc',
         'dns/dns_response.h',
         'dns/dns_session.cc',
         'dns/dns_session.h',
         'dns/dns_transaction.cc',
@@ skipping 1480 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',
           ],
         },
       ],
     }],
   ],
 }