Add Mojo types and service definitions for Background Sync API

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 561 matching lines @@
       'browser/web_contents/aura/overscroll_window_delegate_unittest.cc',
       'browser/web_contents/web_contents_delegate_unittest.cc',
       'browser/web_contents/web_contents_impl_unittest.cc',
       'browser/web_contents/web_contents_user_data_unittest.cc',
       'browser/web_contents/web_contents_view_mac_unittest.mm',
       'browser/web_contents/web_drag_dest_mac_unittest.mm',
       'browser/web_contents/web_drag_source_mac_unittest.mm',
       'browser/webui/url_data_manager_backend_unittest.cc',
       'browser/webui/web_ui_data_source_unittest.cc',
       'browser/webui/web_ui_message_handler_unittest.cc',
+      'child/background_sync/background_sync_type_converters_unittest.cc',
       'child/blink_platform_impl_unittest.cc',
       'child/fileapi/webfilewriter_base_unittest.cc',
       'child/indexed_db/indexed_db_dispatcher_unittest.cc',
       'child/indexed_db/webidbcursor_impl_unittest.cc',
       'child/multipart_response_delegate_unittest.cc',
       'child/notifications/notification_data_conversions_unittest.cc',
       'child/power_monitor_broadcast_source_unittest.cc',
       'child/resource_dispatcher_unittest.cc',
       'child/service_worker/service_worker_dispatcher_unittest.cc',
       'child/simple_webmimeregistry_impl_unittest.cc',
@@ skipping 1550 matching lines @@
                   'files': ['<(PRODUCT_DIR)/libnpapi_test_plugin.so'],
                 },
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }