Add ash::VPNDelegate and Chrome OS implementation

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;
+  return network.vpn_provider_extension_id().empty();

[stevenjb, 2015/03/12 17:40:45]

We should comment this. It seems at some point we might want to store
Provider.Type here to and compare that, but for now I think a comment will
suffice, e.g. something like 'If no provider extension id is specified, match
any built-in VPN type'.

[bartfab (slow), 2015/03/17 12:38:21]

Done.

+}
+
+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