Remove KeyboardDevice class.

ui/events/devices/events_devices.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 12 matching lines @@
       'sources': [
         'device_data_manager.cc',
         'device_data_manager.h',
         'device_hotplug_event_observer.h',
         'device_util_linux.cc',
         'device_util_linux.h',
         'events_devices_export.h',
         'input_device.cc',
         'input_device.h',
         'input_device_event_observer.h',
-        'keyboard_device.cc',
-        'keyboard_device.h',
         'touchscreen_device.cc',
         'touchscreen_device.h',
       ],
       'export_dependent_settings': [
         '../../../ui/gfx/gfx.gyp:gfx',
       ],
     },
   ],
 }