Add WiFi SSID getter to NetworkChangeNotifier.

net/android/network_change_notifier_android.cc

Index: net/android/network_change_notifier_android.cc
diff --git a/net/android/network_change_notifier_android.cc b/net/android/network_change_notifier_android.cc
index 0a109b81fac1b210daf214f6949b6fe68ec910f2..9497fc21b9a0b83074e683d161f83de0a2e40866 100644
--- a/net/android/network_change_notifier_android.cc
+++ b/net/android/network_change_notifier_android.cc
@@ -114,6 +114,11 @@ NetworkChangeNotifierAndroid::GetCurrentConnectionType() const {
   return delegate_->GetCurrentConnectionType();
 }
 
+std::string NetworkChangeNotifierAndroid::GetCurrentWiFiSSID() const {
+  // Not implemented. See https://crbug.com/451272
+  return "";
+}
+
 double NetworkChangeNotifierAndroid::GetCurrentMaxBandwidth() const {
   return delegate_->GetCurrentMaxBandwidth();
 }