Use Blink accessibility enums in Chromium

content/content_common.gypi

 # 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../components/tracing.gyp:tracing',
     '../net/net.gyp:net',
     '../skia/skia.gyp:skia',
@@ skipping 84 matching lines @@
     'public/common/top_controls_state_list.h',
     'public/common/url_constants.cc',
     'public/common/url_constants.h',
     'public/common/url_fetcher.h',
     'public/common/url_utils.cc',
     'public/common/url_utils.h',
     'public/common/webplugininfo.cc',
     'public/common/webplugininfo.h',
     'public/common/zygote_fork_delegate_linux.h',
     'common/accessibility_messages.h',
-    'common/accessibility_notification.h',
     'common/accessibility_node_data.cc',
     'common/accessibility_node_data.h',
     'common/all_messages.h',
     'common/android/address_parser.cc',
     'common/android/address_parser.h',
     'common/android/address_parser_internal.cc',
     'common/android/address_parser_internal.h',
     'common/android/command_line.cc',
     'common/android/command_line.h',
     'common/android/common_jni_registrar.cc',
@@ skipping 456 matching lines @@
         '..\\third_party\\directxsdk\\files\\Redist\\<(input)',
         '<(output)',
         '<(PRODUCT_DIR)',
         ],
         'msvs_cygwin_shell': 1,
       },
      ]
     }],
   ],
 }