net/dns: Fix the last warning found by chromium-style clang plugin on Windows.

net/dns/dns_config_service_win.cc

Index: net/dns/dns_config_service_win.cc
diff --git a/net/dns/dns_config_service_win.cc b/net/dns/dns_config_service_win.cc
index 9d698c6f28e76b5c85ddfcfd2f4bf413d5d30669..aa17a32848a4540ceb1dbba8b0f525485feed7b5 100644
--- a/net/dns/dns_config_service_win.cc
+++ b/net/dns/dns_config_service_win.cc
@@ -436,6 +436,21 @@ void ConfigureSuffixSearch(const DnsSystemSettings& settings,
 
 }  // namespace
 
+DnsSystemSettings::DnsSystemSettings()
+    : policy_search_list(),
+      tcpip_search_list(),
+      tcpip_domain(),
+      primary_dns_suffix(),
+      policy_devolution(),
+      dnscache_devolution(),
+      tcpip_devolution(),
+      append_to_multi_label_name(),
+      have_name_resolution_policy(false) {
+}
+
+DnsSystemSettings::~DnsSystemSettings() {
+}
+
 bool ParseSearchList(const base::string16& value,
                      std::vector<std::string>* output) {
   DCHECK(output);