Add integraton test for sync backup/rollback.

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 2362 matching lines @@
         'browser/sync/test/integration/passwords_helper.cc',
         'browser/sync/test/integration/passwords_helper.h',
         'browser/sync/test/integration/preferences_helper.cc',
         'browser/sync/test/integration/preferences_helper.h',
         'browser/sync/test/integration/search_engines_helper.cc',
         'browser/sync/test/integration/search_engines_helper.h',
         'browser/sync/test/integration/sessions_helper.cc',
         'browser/sync/test/integration/sessions_helper.h',
         'browser/sync/test/integration/single_client_app_list_sync_test.cc',
         'browser/sync/test/integration/single_client_apps_sync_test.cc',
+        'browser/sync/test/integration/single_client_backup_rollback_test.cc',
         'browser/sync/test/integration/single_client_bookmarks_sync_test.cc',
         'browser/sync/test/integration/single_client_dictionary_sync_test.cc',
         'browser/sync/test/integration/single_client_extensions_sync_test.cc',
         'browser/sync/test/integration/single_client_managed_user_settings_sync_test.cc',
         'browser/sync/test/integration/single_client_passwords_sync_test.cc',
         'browser/sync/test/integration/single_client_preferences_sync_test.cc',
         'browser/sync/test/integration/single_client_search_engines_sync_test.cc',
         'browser/sync/test/integration/single_client_sessions_sync_test.cc',
         'browser/sync/test/integration/single_client_themes_sync_test.cc',
         'browser/sync/test/integration/single_client_typed_urls_sync_test.cc',
@@ skipping 609 matching lines @@
             ['enable_webrtc==1', {
               'dependencies': [
                 '../third_party/libjingle/libjingle.gyp:libjingle_webrtc'
               ]
             }],
           ],
         }]
     }],
   ],  # 'conditions'
 }