Don't require expectations file for DumpAccessibility tests.

content/content_tests.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': {
     'layouttest_support_content_sources': [
       'public/test/layouttest_support.h',
       'public/test/nested_message_pump_android.cc',
       'public/test/nested_message_pump_android.h',
@@ skipping 1490 matching lines @@
                 },
               },
               # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
               'msvs_disabled_warnings': [ 4267, ],
             }],
             ['OS=="win" and win_use_allocator_shim==1', {
               'dependencies': [
                 '../base/allocator/allocator.gyp:allocator',
               ],
             }],
-            ['OS=="linux"', {
-              'sources!': [
-                'browser/accessibility/dump_accessibility_tree_browsertest.cc',
-              ],
-            }],
             ['OS=="android"', {
               'sources': [ '<@(content_browsertests_android_sources)' ],
               'sources!': [
                 'browser/battery_status/battery_monitor_impl_browsertest.cc',
               ],
               'dependencies': [
                 'content_shell_jni_headers',
                 'content_shell_lib',
                 '../testing/android/native_test.gyp:native_test_support',
               ],
@@ skipping 671 matching lines @@
                   'content_unittests_apk.isolate',
                 ],
               },
             ],
           },
         ],
       ],
     }],
   ],
 }