Simplify code for VPN entries in system menu

ash/system/network/vpn_list_view.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 ASH_SYSTEM_NETWORK_VPN_LIST_VIEW_H_
 #define ASH_SYSTEM_NETWORK_VPN_LIST_VIEW_H_
 
 #include <map>
 #include <string>
 
 #include "ash/system/network/network_list_view_base.h"
 #include "ash/system/network/vpn_list.h"
-#include "ash/system/tray/view_click_listener.h"
 #include "base/macros.h"
 #include "chromeos/network/network_state_handler.h"
 
 namespace chromeos {
 class NetworkState;
 }
 
 namespace views {
 class View;
 }
 
 namespace ash {
 namespace tray {
 class NetworkStateListDetailedView;
 }
 
 // A list of VPN providers and networks that shows VPN providers and networks in
 // a hierarchical layout, allowing the user to see at a glance which provider a
 // network belongs to. The only exception is the currently connected or
 // connecting network, which is detached from its provider and moved to the top.
 // If there is a connected network, a disconnect button is shown next to its
 // name.
 //
 // Disconnected networks are arranged in shill's priority order within each
 // provider and the providers are arranged in the order of their highest
 // priority network. Clicking on a disconnected network triggers a connection
 // attempt. Clicking on the currently connected or connecting network shows its
 // configuration dialog. Clicking on a provider shows the provider's "add
 // network" dialog.
-class VPNListView : public NetworkListViewBase,
-                    public VpnList::Observer,
-                    public ViewClickListener {
+class VPNListView : public NetworkListViewBase, public VpnList::Observer {
  public:
   explicit VPNListView(tray::NetworkStateListDetailedView* detailed_view);
   ~VPNListView() override;
 
   // NetworkListViewBase:
   void Update() override;
   bool IsNetworkEntry(views::View* view, std::string* guid) const override;
 
   // VpnList::Observer:
   void OnVPNProvidersChanged() override;
 
-  // ViewClickListener:
-  void OnViewClicked(views::View* sender) override;
-
  private:
   // Adds a network to the list.
   void AddNetwork(const chromeos::NetworkState* network);
 
   // Adds the VPN provider identified by |vpn_provider| to the list, along with
   // any networks that belong to this provider.
   void AddProviderAndNetworks(
       const VPNProvider& vpn_provider,
       const chromeos::NetworkStateHandler::NetworkStateList& networks);
 
@@ skipping 10 matching lines @@
   // Whether the list is currently empty (i.e., the next entry added will become
   // the topmost entry).
   bool list_empty_ = true;
 
   DISALLOW_COPY_AND_ASSIGN(VPNListView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_NETWORK_VPN_LIST_VIEW_H_