Remove last MD reference from TrayPopupUtils.

ui/views/BUILD.gn

 # 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.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 import("//ui/ozone/ozone.gni")
 import("//ui/vector_icons/vector_icons.gni")
@@ skipping 143 matching lines @@
     "controls/focusable_rounded_border_mac.h",
     "controls/glow_hover_controller.cc",
     "controls/glow_hover_controller.h",
     "controls/image_view.cc",
     "controls/image_view.h",
     "controls/label.cc",
     "controls/label.h",
     "controls/link.cc",
     "controls/link.h",
     "controls/link_listener.h",
-    "controls/md_slider.cc",
-    "controls/md_slider.h",
     "controls/menu/display_change_listener_mac.cc",
     "controls/menu/menu_config.cc",
     "controls/menu/menu_config.h",
     "controls/menu/menu_config_chromeos.cc",
     "controls/menu/menu_config_linux.cc",
     "controls/menu/menu_config_mac.mm",
     "controls/menu/menu_config_win.cc",
     "controls/menu/menu_controller.cc",
     "controls/menu/menu_controller.h",
     "controls/menu/menu_controller_delegate.h",
@@ skipping 33 matching lines @@
     "controls/menu/native_menu_win.cc",
     "controls/menu/native_menu_win.h",
     "controls/menu/submenu_view.cc",
     "controls/menu/submenu_view.h",
     "controls/message_box_view.cc",
     "controls/message_box_view.h",
     "controls/native/native_view_host.cc",
     "controls/native/native_view_host.h",
     "controls/native/native_view_host_mac.h",
     "controls/native/native_view_host_mac.mm",
-    "controls/non_md_slider.cc",
-    "controls/non_md_slider.h",
     "controls/prefix_delegate.h",
     "controls/prefix_selector.cc",
     "controls/prefix_selector.h",
     "controls/progress_bar.cc",
     "controls/progress_bar.h",
     "controls/resize_area.cc",
     "controls/resize_area.h",
     "controls/resize_area_delegate.h",
     "controls/scroll_view.cc",
     "controls/scroll_view.h",
@@ skipping 479 matching lines @@
     "test/menu_test_utils.cc",
     "test/menu_test_utils.h",
     "test/native_widget_factory.h",
     "test/scoped_views_test_helper.cc",
     "test/scoped_views_test_helper.h",
     "test/slider_test_api.cc",
     "test/slider_test_api.h",
     "test/test_layout_manager.cc",
     "test/test_layout_manager.h",
     "test/test_platform_native_widget.h",
-    "test/test_slider.cc",
-    "test/test_slider.h",
     "test/test_views.cc",
     "test/test_views.h",
     "test/test_views_delegate.h",
     "test/test_views_delegate_mac.mm",
     "test/test_widget_observer.cc",
     "test/test_widget_observer.h",
     "test/views_interactive_ui_test_base.cc",
     "test/views_interactive_ui_test_base.h",
     "test/views_test_base.cc",
     "test/views_test_base.h",
@@ skipping 321 matching lines @@
       "//ui/base:test_support",
       "//ui/compositor",
       "//ui/events:test_support",
       "//ui/gl:test_support",
       "//ui/resources",
       "//ui/resources:ui_test_pak",
       "//ui/strings",
     ]
   }
 }