Add WiFi SSID getter to NetworkChangeNotifier.

net/base/network_change_notifier_win.cc

Index: net/base/network_change_notifier_win.cc
diff --git a/net/base/network_change_notifier_win.cc b/net/base/network_change_notifier_win.cc
index 05125941767c3fa2eed83504c1b2b51354999670..51340cb46973a61ea7a92b2490fb14d4fa3c9104 100644
--- a/net/base/network_change_notifier_win.cc
+++ b/net/base/network_change_notifier_win.cc
@@ -217,6 +217,11 @@ NetworkChangeNotifierWin::GetCurrentConnectionType() const {
   return last_computed_connection_type_;
 }
 
+std::string NetworkChangeNotifierWin::GetCurrentWiFiSSID() const {
+  // Not implemented. See https://crbug.com/451272
+  return "";
+}
+
 void NetworkChangeNotifierWin::SetCurrentConnectionType(
     ConnectionType connection_type) {
   base::AutoLock auto_lock(last_computed_connection_type_lock_);