Refactors keyboard related code so mash can use a keyboard

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,
     # These files lists are shared with the GN build.
     'ash_sources': [
       'accelerators/accelerator_commands.cc',
@@ skipping 147 matching lines @@
       'host/ash_window_tree_host_unified.h',
       'host/ash_window_tree_host_win.cc',
       'host/ash_window_tree_host_win.h',
       'host/ash_window_tree_host_x11.cc',
       'host/ash_window_tree_host_x11.h',
       'host/root_window_transformer.h',
       'host/transformer_helper.cc',
       'host/transformer_helper.h',
       'ime/input_method_event_handler.cc',
       'ime/input_method_event_handler.h',
+      'keyboard/keyboard_ui.cc',
+      'keyboard/keyboard_ui.h',
+      'keyboard/keyboard_ui_observer.h',
       'keyboard_uma_event_filter.cc',
       'keyboard_uma_event_filter.h',
       'magnifier/magnification_controller.cc',
       'magnifier/magnification_controller.h',
       'magnifier/partial_magnification_controller.cc',
       'magnifier/partial_magnification_controller.h',
       'metrics/desktop_task_switch_metric_recorder.cc',
       'metrics/desktop_task_switch_metric_recorder.h',
       'metrics/task_switch_metrics_recorder.cc',
       'metrics/task_switch_metrics_recorder.h',
@@ skipping 1174 matching lines @@
                   '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
                 ],
               }
             ],
           ],
         },
       ],
     }],
   ],
 }