mash: Move SystemTrayDelegate ownership to WmShell

ash/system/chromeos/enterprise/tray_enterprise.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/system/chromeos/enterprise/tray_enterprise.h"
 
 #include "ash/common/system/tray/system_tray_delegate.h"
+#include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/system/chromeos/label_tray_view.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/user/login_status.h"
 #include "base/logging.h"
 #include "base/strings/string16.h"
 #include "grit/ash_resources.h"
 
 namespace ash {
 
 TrayEnterprise::TrayEnterprise(SystemTray* system_tray)
     : SystemTrayItem(system_tray),
       tray_view_(NULL) {
   Shell::GetInstance()->system_tray_notifier()->
       AddEnterpriseDomainObserver(this);
 }
 
 TrayEnterprise::~TrayEnterprise() {
   Shell::GetInstance()->system_tray_notifier()->
       RemoveEnterpriseDomainObserver(this);
 }
 
 void TrayEnterprise::UpdateEnterpriseMessage() {
-  base::string16 message = Shell::GetInstance()->system_tray_delegate()->
-      GetEnterpriseMessage();
+  base::string16 message =
+      WmShell::Get()->system_tray_delegate()->GetEnterpriseMessage();
   if (tray_view_)
     tray_view_->SetMessage(message);
 }
 
 views::View* TrayEnterprise::CreateDefaultView(LoginStatus status) {
   CHECK(tray_view_ == NULL);
   // For public accounts, enterprise ownership is indicated in the user details
   // instead.
   if (status == LoginStatus::PUBLIC)
     return NULL;
   tray_view_ = new LabelTrayView(this, IDR_AURA_UBER_TRAY_ENTERPRISE);
   UpdateEnterpriseMessage();
   return tray_view_;
 }
 
 void TrayEnterprise::DestroyDefaultView() {
   tray_view_ = NULL;
 }
 
 void TrayEnterprise::OnEnterpriseDomainChanged() {
   UpdateEnterpriseMessage();
 }
 
 void TrayEnterprise::OnViewClicked(views::View* sender) {
-  Shell::GetInstance()->system_tray_delegate()->ShowEnterpriseInfo();
+  WmShell::Get()->system_tray_delegate()->ShowEnterpriseInfo();
 }
 
 } // namespace ash