Reland: mash: Convert TrayBackgroundView to wm common types

ash/system/tray/media_security/multi_profile_media_tray_item_unittest.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/tray/media_security/multi_profile_media_tray_item.h"
 
 #include "ash/ash_view_ids.h"
+#include "ash/common/system/tray/system_tray_bubble.h"
 #include "ash/common/system/tray/tray_item_view.h"
-#include "ash/shell.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/system_tray.h"
-#include "ash/system/tray/system_tray_bubble.h"
 #include "ash/test/ash_test_base.h"
+#include "ash/test/ash_test_helper.h"
+#include "ash/test/status_area_widget_test_helper.h"
 #include "ash/test/test_session_state_delegate.h"
 #include "ash/test/test_shell_delegate.h"
 #include "ui/views/bubble/tray_bubble_view.h"
 
 namespace ash {
 
 typedef test::AshTestBase MultiProfileMediaTrayItemTest;
 
 TEST_F(MultiProfileMediaTrayItemTest, NotifyMediaCaptureChange) {
   TrayItemView::DisableAnimationsForTest();
   test::TestShellDelegate* shell_delegate =
-      static_cast<test::TestShellDelegate*>(Shell::GetInstance()->delegate());
+      ash_test_helper()->test_shell_delegate();
   test::TestSessionStateDelegate* session_state_delegate =
-      static_cast<test::TestSessionStateDelegate*>(
-          Shell::GetInstance()->session_state_delegate());
+      test::AshTestHelper::GetTestSessionStateDelegate();
   session_state_delegate->set_logged_in_users(2);
 
-  SystemTray* system_tray = Shell::GetInstance()->GetPrimarySystemTray();
+  SystemTray* system_tray = GetPrimarySystemTray();
   system_tray->ShowDefaultView(BUBBLE_CREATE_NEW);
   views::View* in_user_view =
       system_tray->GetSystemBubble()->bubble_view()->GetViewByID(
           VIEW_ID_USER_VIEW_MEDIA_INDICATOR);
 
-  StatusAreaWidget* widget = system_tray->status_area_widget();
+  StatusAreaWidget* widget = StatusAreaWidgetTestHelper::GetStatusAreaWidget();
   EXPECT_TRUE(widget->GetRootView()->visible());
   views::View* tray_view =
       widget->GetRootView()->GetViewByID(VIEW_ID_MEDIA_TRAY_VIEW);
 
   EXPECT_FALSE(tray_view->visible());
   EXPECT_FALSE(in_user_view->visible());
 
   shell_delegate->SetMediaCaptureState(MEDIA_CAPTURE_AUDIO);
   EXPECT_TRUE(tray_view->visible());
   EXPECT_TRUE(in_user_view->visible());
 
   shell_delegate->SetMediaCaptureState(MEDIA_CAPTURE_AUDIO_VIDEO);
   EXPECT_TRUE(tray_view->visible());
   EXPECT_TRUE(in_user_view->visible());
 
   shell_delegate->SetMediaCaptureState(MEDIA_CAPTURE_NONE);
   EXPECT_FALSE(tray_view->visible());
   EXPECT_FALSE(in_user_view->visible());
 }
 
 }  // namespace ash