Avoid initial NetworkChangeNotifier OnDNSChanged() signal on Android

net/dns/dns_config_service_unittest.cc

Index: net/dns/dns_config_service_unittest.cc
diff --git a/net/dns/dns_config_service_unittest.cc b/net/dns/dns_config_service_unittest.cc
index e3abafd20aa11ffad63e9b40fc0aadfed47535da..be3cacd9c5c89daa7ecd668a12ccd3ca3235b3d3 100644
--- a/net/dns/dns_config_service_unittest.cc
+++ b/net/dns/dns_config_service_unittest.cc
@@ -335,6 +335,10 @@ TEST_F(DnsConfigServiceTest, WatchFailure) {
 #if (defined(OS_POSIX) && !defined(OS_ANDROID)) || defined(OS_WIN)
 // TODO(szym): This is really an integration test and can time out if HOSTS is
 // huge. http://crbug.com/107810
+// On Android the hosts file is not user modifyable, so it's always tiny,
+// however devices used for testing are likely to have no network connectivity
+// and hence no DNS configuration so this test will just fail to find a valid
+// config.
 TEST_F(DnsConfigServiceTest, DISABLED_GetSystemConfig) {
   service_.reset();
   scoped_ptr<DnsConfigService> service(DnsConfigService::CreateSystemService());