mash: Convert system tray logout button to wm common types

ash/common/system/tray/system_tray_delegate.h

 // Copyright (c) 2012 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_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 #define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 109 matching lines @@
 // implementations of this class. Consumers of this delegate should handle the
 // default return value (e.g. nullptr).
 class ASH_EXPORT SystemTrayDelegate {
  public:
   SystemTrayDelegate();
   virtual ~SystemTrayDelegate();
 
   // Called after SystemTray has been instantiated.
   virtual void Initialize();
 
-  // Called before SystemTray is destroyed.
-  virtual void Shutdown();
-
   // Returns true if system tray should be visible on startup.
   virtual bool GetTrayVisibilityOnStartup();
 
   // Gets information about the active user.
   virtual LoginStatus GetUserLoginStatus() const;
 
   // Shows UI for changing user's profile picture.
   virtual void ChangeProfilePicture();
 
   // Returns the domain that manages the device, if it is enterprise-enrolled.
@@ skipping 193 matching lines @@
   // asynchronously calls |callback| once a trusted policy becomes available.
   virtual void ShouldRebootOnShutdown(const RebootOnShutdownCallback& callback);
 
   // Returns VPNDelegate. May return nullptr.
   virtual VPNDelegate* GetVPNDelegate() const;
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_