Extract ResultCatcher from ExtensionApiTest. Use it in ShellApiTest.

chrome/chrome_tests.gypi

 # Copyright 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.
 {
   'includes': [
     'js_unittest_vars.gypi',
   ],
   'targets': [
     {
       'target_name': 'interactive_ui_tests',
@@ skipping 1083 matching lines @@
         'browser/extensions/api/content_settings/content_settings_apitest.cc',
         'browser/extensions/api/context_menus/context_menu_apitest.cc',
         'browser/extensions/api/cookies/cookies_apitest.cc',
         'browser/extensions/api/debugger/debugger_apitest.cc',
         'browser/extensions/api/debugger/debugger_extension_apitest.cc',
         'browser/extensions/api/declarative/declarative_apitest.cc',
         'browser/extensions/api/declarative_content/declarative_content_apitest.cc',
         'browser/extensions/api/desktop_capture/desktop_capture_apitest.cc',
         'browser/extensions/api/developer_private/developer_private_apitest.cc',
         'browser/extensions/api/dial/dial_apitest.cc',
-        'browser/extensions/api/dns/dns_apitest.cc',
         'browser/extensions/api/downloads/downloads_api_browsertest.cc',
         'browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc',
         'browser/extensions/api/extension_action/browser_action_apitest.cc',
         'browser/extensions/api/extension_action/browser_action_browsertest.cc',
         'browser/extensions/api/extension_action/page_action_apitest.cc',
         'browser/extensions/api/feedback_private/feedback_private_apitest.cc',
         'browser/extensions/api/feedback_private/feedback_browsertest.cc',
         'browser/extensions/api/file_system/file_system_apitest.cc',
         'browser/extensions/api/file_system/file_system_apitest_chromeos.cc',
         'browser/extensions/api/font_settings/font_settings_apitest.cc',
@@ skipping 1949 matching lines @@
             ['enable_webrtc==1', {
               'dependencies': [
                 '../third_party/libjingle/libjingle.gyp:libjingle_webrtc'
               ]
             }],
           ],
         }]
     }],
   ],  # 'conditions'
 }