Remove keyboard usability mode

ash/ash.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
     'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/chrome',
     # These files lists are shared with the GN build.
     'ash_sources': [
@@ skipping 84 matching lines @@
       'display/resolution_notification_controller.cc',
       'display/resolution_notification_controller.h',
       'display/root_window_transformers.cc',
       'display/root_window_transformers.h',
       'display/screen_ash.cc',
       'display/screen_ash.h',
       'display/screen_position_controller.cc',
       'display/screen_position_controller.h',
       'display/shared_display_edge_indicator.cc',
       'display/shared_display_edge_indicator.h',
-      'display/virtual_keyboard_window_controller.cc',
-      'display/virtual_keyboard_window_controller.h',
       'drag_drop/drag_drop_controller.cc',
       'drag_drop/drag_drop_controller.h',
       'drag_drop/drag_drop_tracker.cc',
       'drag_drop/drag_drop_tracker.h',
       'drag_drop/drag_image_view.cc',
       'drag_drop/drag_image_view.h',
       'first_run/desktop_cleaner.cc',
       'first_run/desktop_cleaner.h',
       'first_run/first_run_helper.cc',
       'first_run/first_run_helper.h',
@@ skipping 651 matching lines @@
       'autoclick/autoclick_unittest.cc',
       'desktop_background/desktop_background_controller_unittest.cc',
       'desktop_background/wallpaper_resizer_unittest.cc',
       'dip_unittest.cc',
       'display/display_change_observer_chromeos_unittest.cc',
       'display/display_controller_unittest.cc',
       'display/display_error_observer_chromeos_unittest.cc',
       'display/display_info_unittest.cc',
       'display/display_manager_unittest.cc',
       'display/mirror_window_controller_unittest.cc',
-      'display/virtual_keyboard_window_controller_unittest.cc',
       'display/mouse_cursor_event_filter_unittest.cc',
       'display/projecting_observer_chromeos_unittest.cc',
       'display/resolution_notification_controller_unittest.cc',
       'display/root_window_transformers_unittest.cc',
       'display/screen_position_controller_unittest.cc',
       'drag_drop/drag_drop_controller_unittest.cc',
       'drag_drop/drag_drop_tracker_unittest.cc',
       'extended_desktop_unittest.cc',
       'focus_cycler_unittest.cc',
       'frame/caption_buttons/frame_caption_button_container_view_unittest.cc',
@@ skipping 480 matching lines @@
       'conditions': [
         ['chromeos==1', {
           'dependencies': [
             '../ui/display/display.gyp:display',
           ],
         }],
       ],
     },
   ],
 }