Add ash UI for third-party VPNs

ui/chromeos/network/network_list_view_base.h

+// 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.
+
+#ifndef UI_CHROMEOS_NETWORK_NETWORK_LIST_VIEW_BASE_H_
+#define UI_CHROMEOS_NETWORK_NETWORK_LIST_VIEW_BASE_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "ui/chromeos/ui_chromeos_export.h"
+
+namespace views {
+class View;
+}
+
+namespace ui {
+
+// Base class for a list of available networks (and, in the case of VPNs, the
+// list of available VPN providers).
+class UI_CHROMEOS_EXPORT NetworkListViewBase {
+ public:
+  NetworkListViewBase();
+  virtual ~NetworkListViewBase();
+
+  void set_container(views::View* container) {
+    container_ = container;
+  }
+
+  // Refreshes the network list.
+  virtual void Update() = 0;
+
+  // Checks whether |view| represents a network in the list. If yes, sets
+  // |service_path| to the network's service path and returns |true|. Otherwise,
+  // leaves |sevice_path| unchanged and returns |false|.
+  virtual bool IsNetworkEntry(views::View* view,
+                              std::string* service_path) const = 0;
+
+ protected:
+  // The container that holds the actual list entries.
+  views::View* container_ = nullptr;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NetworkListViewBase);
+};
+
+}  // namespace ui
+
+#endif  // UI_CHROMEOS_NETWORK_NETWORK_LIST_VIEW_BASE_H_