Add an ONC property for the third-party VPN provider extension ID

ash/system/chromeos/network/vpn_delegate.cc

 // Copyright 2015 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.
 
 #include "ash/system/chromeos/network/vpn_delegate.h"
 
 #include "chromeos/network/network_state.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 
 namespace ash {
 
 VPNProvider::Key::Key() : third_party(false) {
 }
 
 VPNProvider::Key::Key(const std::string& extension_id)
     : third_party(true), extension_id(extension_id) {
 }
 
 bool VPNProvider::Key::operator==(const Key& other) const {
   return other.third_party == third_party && other.extension_id == extension_id;
 }
 
 bool VPNProvider::Key::MatchesNetwork(
     const chromeos::NetworkState& network) const {
   if (network.type() != shill::kTypeVPN)
     return false;
-  if (third_party)
-    return network.vpn_provider_extension_id() == extension_id;
-  // Currently, all networks with an empty |vpn_provider_extension_id| use a
-  // single built-in VPN providers. In the future, we may distinguish between
-  // multiple built-in providers based on the |Provider.Type| property.
-  return network.vpn_provider_extension_id().empty();
+  const bool network_uses_third_party_provider =
+      network.vpn_provider_type() == shill::kProviderThirdPartyVpn;
+  if (!third_party)
+    return !network_uses_third_party_provider;
+  return network_uses_third_party_provider &&
+         network.third_party_vpn_provider_extension_id() == extension_id;
 }
 
 VPNProvider::VPNProvider(const Key& key, const std::string& name)
     : key(key), name(name) {
 }
 
 VPNDelegate::Observer::~Observer() {
 }
 
 VPNDelegate::VPNDelegate() {
 }
 
 VPNDelegate::~VPNDelegate() {
 }
 
 void VPNDelegate::AddObserver(Observer* observer) {
   observer_list_.AddObserver(observer);
 }
 
 void VPNDelegate::RemoveObserver(Observer* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
 void VPNDelegate::NotifyObservers() {
   FOR_EACH_OBSERVER(Observer, observer_list_, OnVPNProvidersChanged());
 }
 
 }  // namespace ash