chromeos: Remove AshTestBase::SupportsMultipleDisplays

ash/system/web_notification/web_notification_tray_unittest.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/web_notification/web_notification_tray.h"
 
 #include <utility>
 #include <vector>
 
 #include "ash/common/material_design/material_design_controller.h"
@@ skipping 248 matching lines @@
   GetTray()->ShowPopups();
   EXPECT_TRUE(GetTray()->IsPopupVisible());
   EXPECT_EQ(notifications_to_add, GetMessageCenter()->NotificationCount());
   NotificationList::PopupNotifications popups =
       GetMessageCenter()->GetPopupNotifications();
   EXPECT_EQ(message_center::kMaxVisiblePopupNotifications, popups.size());
 }
 
 // Verifies if the notification appears on both displays when extended mode.
 TEST_P(WebNotificationTrayTest, PopupShownOnBothDisplays) {
-  if (!SupportsMultipleDisplays())
-    return;
-
   Shell::GetInstance()
       ->screen_layout_observer()
       ->set_show_notifications_for_testing(true);
   UpdateDisplay("400x400,200x200");
   // UpdateDisplay() creates the display notifications, so popup is visible.
   EXPECT_TRUE(GetTray()->IsPopupVisible());
   WebNotificationTray* secondary_tray = GetSecondaryTray();
   ASSERT_TRUE(secondary_tray);
   EXPECT_TRUE(secondary_tray->IsPopupVisible());
 
@@ skipping 221 matching lines @@
   gfx::Point out_of_bounds(bounds.x() - 1, center_point.y());
   generator.MoveTouch(out_of_bounds);
   EXPECT_FALSE(tray->is_active());
 
   generator.ReleaseTouch();
   EXPECT_FALSE(tray->is_active());
   EXPECT_FALSE(tray->IsMessageCenterBubbleVisible());
 }
 
 }  // namespace ash