Convert enable_pre_sync_backup flag to new flags system.

components/components_tests.gyp

 # Copyright 2014 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': {
     # This turns on e.g. the filename-based detection of which
     # platforms to include source files on (e.g. files ending in
     # _mac.h or _mac.cc are only compiled on MacOSX).
     'chromium_code': 1,
@@ skipping 1032 matching lines @@
         'components.gyp:search_engines',
         'components.gyp:search_engines_test_support',
         'components.gyp:search_provider_logos',
         'components.gyp:sessions_test_support',
         'components.gyp:signin_core_browser',
         'components.gyp:signin_core_browser_test_support',
         'components.gyp:ssl_config',
         'components.gyp:ssl_errors',
         'components.gyp:suggestions',
         'components.gyp:sync_bookmarks',
+        'components.gyp:sync_driver_features',
         'components.gyp:sync_driver_test_support',
         'components.gyp:sync_sessions',
         'components.gyp:sync_sessions_test_support',
         'components.gyp:syncable_prefs_test_support',
         'components.gyp:translate_core_browser',
         'components.gyp:translate_core_common',
         'components.gyp:translate_core_language_detection',
         'components.gyp:ui_zoom',
         'components.gyp:undo_component',
         'components.gyp:update_client',
@@ skipping 784 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }