Display "Restart to update" dialog to Chrome OS users.

ash/common/system/tray/system_tray_controller.h

 // Copyright 2016 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_CONTROLLER_H_
 #define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/public/interfaces/system_tray.mojom.h"
 #include "base/compiler_specific.h"
@@ skipping 33 matching lines @@
   void ShowAccessibilitySettings();
   void ShowPaletteHelp();
   void ShowPaletteSettings();
   void ShowPublicAccountInfo();
   void ShowNetworkConfigure(const std::string& network_id);
   void ShowNetworkCreate(const std::string& type);
   void ShowThirdPartyVpnCreate(const std::string& extension_id);
   void ShowNetworkSettings(const std::string& network_id);
   void ShowProxySettings();
   void SignOut();
-  void RequestRestartForUpdate();
+  void RequestRestartForUpdate(bool always_reboot);

[James Cook, 2016/11/30 23:01:40]

Can the "always_reboot" information be cached in the src/chrome layer so that
src/ash doesn't need to know about it?

From the UI perspective it just needs to show the reboot menu item, it doesn't
care why.

 
   // Binds the mojom::SystemTray interface to this object.
   void BindRequest(mojom::SystemTrayRequest request);
 
  private:
   // mojom::SystemTray:
   void SetClient(mojom::SystemTrayClientPtr client) override;
   void SetUse24HourClock(bool use_24_hour) override;
 
   // Client interface in chrome browser. Only bound on Chrome OS.
   mojom::SystemTrayClientPtr system_tray_client_;
 
   // Bindings for the SystemTray interface.
   mojo::BindingSet<mojom::SystemTray> bindings_;
 
   // The type of clock hour display: 12 or 24 hour.
   base::HourClockType hour_clock_type_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemTrayController);
 };
 
 }  // namspace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_CONTROLLER_H_