mash: Migrate remaining tray observers and notify functions.

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/login_status.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
+#include "ash/common/system/tray/system_tray_notifier.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 "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);
+  WmShell::Get()->system_tray_notifier()->AddEnterpriseDomainObserver(this);
 }
 
 TrayEnterprise::~TrayEnterprise() {
-  Shell::GetInstance()->system_tray_notifier()->
-      RemoveEnterpriseDomainObserver(this);
+  WmShell::Get()->system_tray_notifier()->RemoveEnterpriseDomainObserver(this);
 }
 
 void TrayEnterprise::UpdateEnterpriseMessage() {
   base::string16 message =
       WmShell::Get()->system_tray_delegate()->GetEnterpriseMessage();
   if (tray_view_)
     tray_view_->SetMessage(message);
 }
 
 views::View* TrayEnterprise::CreateDefaultView(LoginStatus status) {
@@ skipping 13 matching lines @@
 
 void TrayEnterprise::OnEnterpriseDomainChanged() {
   UpdateEnterpriseMessage();
 }
 
 void TrayEnterprise::OnViewClicked(views::View* sender) {
   WmShell::Get()->system_tray_delegate()->ShowEnterpriseInfo();
 }
 
 } // namespace ash