ash: Use system tray mojo interface to show system update tray icon

ash/common/system/tray/system_tray_delegate.cc

 // 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.
 
 #include "ash/common/system/tray/system_tray_delegate.h"
 
 #include "ash/common/system/tray/ime_info.h"
 #include "ash/common/system/tray/system_tray_item.h"
 
 namespace ash {
 
 BluetoothDeviceInfo::BluetoothDeviceInfo()
     : connected(false), connecting(false), paired(false) {}
 
 BluetoothDeviceInfo::BluetoothDeviceInfo(const BluetoothDeviceInfo& other) =
     default;
 
 BluetoothDeviceInfo::~BluetoothDeviceInfo() {}
 
-UpdateInfo::UpdateInfo()
-    : severity(UPDATE_NONE),
-      update_required(false),
-      factory_reset_required(false) {}
-
-UpdateInfo::~UpdateInfo() {}
-
 SystemTrayDelegate::SystemTrayDelegate() {}
 
 SystemTrayDelegate::~SystemTrayDelegate() {}
 
 void SystemTrayDelegate::Initialize() {}
 
 LoginStatus SystemTrayDelegate::GetUserLoginStatus() const {
   return LoginStatus::NOT_LOGGED_IN;
 }
 
@@ skipping 22 matching lines @@
 }
 
 bool SystemTrayDelegate::IsUserSupervised() const {
   return false;
 }
 
 bool SystemTrayDelegate::IsUserChild() const {
   return false;
 }
 
-void SystemTrayDelegate::GetSystemUpdateInfo(UpdateInfo* info) const {
-  info->severity = UpdateInfo::UPDATE_NONE;
-  info->update_required = false;
-  info->factory_reset_required = false;
-}
-
 bool SystemTrayDelegate::ShouldShowSettings() const {
   return false;
 }
 
 bool SystemTrayDelegate::ShouldShowNotificationTray() const {
   return false;
 }
 
 void SystemTrayDelegate::ShowEnterpriseInfo() {}
 
@@ skipping 68 matching lines @@
 
 void SystemTrayDelegate::RemoveCustodianInfoTrayObserver(
     CustodianInfoTrayObserver* observer) {}
 
 std::unique_ptr<SystemTrayItem> SystemTrayDelegate::CreateRotationLockTrayItem(
     SystemTray* tray) {
   return nullptr;
 }
 
 }  // namespace ash