Add test for accessibility histograms.

chrome/chrome_tests.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.
 {
   'variables' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
       'common/pref_names.cc',
@@ skipping 857 matching lines @@
       'defines': [
         'HAS_OUT_OF_PROC_TEST_RUNNER',
       ],
       'sources': [
         'app/breakpad_mac_stubs.mm',
         'app/chrome_command_ids.h',
         'app/chrome_dll.rc',
         'app/chrome_dll_resource.h',
         'app/chrome_version.rc.version',
         'browser/accessibility/accessibility_extension_apitest.cc',
+        'browser/accessibility/browser_accessibility_state_browsertest.cc',
         'browser/app_controller_mac_browsertest.mm',
         'browser/autocomplete/autocomplete_browsertest.cc',
         'browser/autofill/autofill_browsertest.cc',
         'browser/autofill/autofill_external_delegate_browsertest.cc',
         'browser/autofill/form_structure_browsertest.cc',
         'browser/automation/automation_misc_browsertest.cc',
         'browser/automation/automation_tab_helper_browsertest.cc',
         'browser/browser_encoding_browsertest.cc',
         'browser/browsing_data/browsing_data_database_helper_browsertest.cc',
         'browser/browsing_data/browsing_data_helper_browsertest.h',
@@ skipping 1970 matching lines @@
             'sync_integration_tests.isolate',
           ],
           'sources': [
             'sync_integration_tests.isolate',
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }