Make LogoutButtonTray a regular View

ash/system/network/tray_vpn.h

Index: ash/system/network/tray_vpn.h
diff --git a/ash/system/network/tray_vpn.h b/ash/system/network/tray_vpn.h
index 93d361d5fe238017cfc3c4298200c93426e83a3b..21a4bd69f0ed2b6381e77edbf1fd8ff8ee0c8237 100644
--- a/ash/system/network/tray_vpn.h
+++ b/ash/system/network/tray_vpn.h
@@ -26,14 +26,10 @@ class TrayVPN : public SystemTrayItem,
   ~TrayVPN() override;
 
   // SystemTrayItem
-  views::View* CreateTrayView(LoginStatus status) override;
   views::View* CreateDefaultView(LoginStatus status) override;
   views::View* CreateDetailedView(LoginStatus status) override;
-  void DestroyTrayView() override;
   void DestroyDefaultView() override;
   void DestroyDetailedView() override;
-  void UpdateAfterLoginStatusChange(LoginStatus status) override;
-  void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override;
 
   // TrayNetworkStateObserver::Delegate
   void NetworkStateChanged() override;