Reimplement automation API on top of C++-backed AXTree.

chrome/chrome_browser_extensions.gypi

 # Copyright (c) 2013 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': {
     'chrome_browser_extensions_chromeos_sources': [
       'browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_api.cc',
       'browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_api.h',
       'browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api.cc',
@@ skipping 120 matching lines @@
       'browser/extensions/api/autofill_private/autofill_private_event_router.h',
       'browser/extensions/api/autofill_private/autofill_private_event_router_factory.cc',
       'browser/extensions/api/autofill_private/autofill_private_event_router_factory.h',
       'browser/extensions/api/autofill_private/autofill_util.cc',
       'browser/extensions/api/autofill_private/autofill_util.h',
       'browser/extensions/api/automation_internal/automation_action_adapter.h',
       'browser/extensions/api/automation_internal/automation_event_router.cc',
       'browser/extensions/api/automation_internal/automation_event_router.h',
       'browser/extensions/api/automation_internal/automation_internal_api.cc',
       'browser/extensions/api/automation_internal/automation_internal_api.h',
-      'browser/extensions/api/automation_internal/automation_util.cc',
-      'browser/extensions/api/automation_internal/automation_util.h',
+      'browser/extensions/api/automation_internal/automation_web_contents_observer.cc',
+      'browser/extensions/api/automation_internal/automation_web_contents_observer.h',
       'browser/extensions/api/autotest_private/autotest_private_api.cc',
       'browser/extensions/api/autotest_private/autotest_private_api.h',
       'browser/extensions/api/bookmark_manager_private/bookmark_manager_private_api.cc',
       'browser/extensions/api/bookmark_manager_private/bookmark_manager_private_api.h',
       'browser/extensions/api/bookmarks/bookmark_api_constants.cc',
       'browser/extensions/api/bookmarks/bookmark_api_constants.h',
       'browser/extensions/api/bookmarks/bookmark_api_helpers.cc',
       'browser/extensions/api/bookmarks/bookmark_api_helpers.h',
       'browser/extensions/api/bookmarks/bookmarks_api.cc',
       'browser/extensions/api/bookmarks/bookmarks_api.h',
@@ skipping 950 matching lines @@
           ],
         }, {  # use_brlapi==0
           'sources': [
             'browser/extensions/api/braille_display_private/braille_controller_stub.cc',
           ],
         }],
       ],
     },
   ],
 }