mash: Convert TrayBackgroundView to wm common types

ash/system/chromeos/session/logout_button_tray.cc

 // Copyright 2014 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/session/logout_button_tray.h"
 
 #include <memory>
 #include <utility>
 
 #include "ash/common/shelf/shelf_types.h"
@@ skipping 77 matching lines @@
   SetBorder(std::move(border));
   set_animate_on_state_change(false);
 
   SetMinSize(gfx::Size(0, kShelfItemHeight));
 }
 
 LogoutButton::~LogoutButton() {
 }
 
 LogoutButtonTray::LogoutButtonTray(StatusAreaWidget* status_area_widget)
-    : TrayBackgroundView(status_area_widget),
+    : TrayBackgroundView(status_area_widget->wm_shelf()),
       button_(NULL),
       login_status_(LoginStatus::NOT_LOGGED_IN),
       show_logout_button_in_tray_(false) {
   button_ = new LogoutButton(this);
   tray_container()->AddChildView(button_);
   tray_container()->SetBorder(views::Border::NullBorder());
   Shell::GetInstance()->system_tray_notifier()->AddLogoutButtonObserver(this);
 }
 
 LogoutButtonTray::~LogoutButtonTray() {
@@ skipping 46 matching lines @@
   UpdateVisibility();
 }
 
 void LogoutButtonTray::UpdateVisibility() {
   SetVisible(show_logout_button_in_tray_ &&
              login_status_ != LoginStatus::NOT_LOGGED_IN &&
              login_status_ != LoginStatus::LOCKED);
 }
 
 }  // namespace ash