chromium/content/test/data/background_sync/test.html

<!DOCTYPE html>
<html>
 <head>
  <title>Background Sync API Test</title>
  <script src="../format_error.js"></script>
  <script src="../result_queue.js"></script>
  <script src="background_sync_test_helpers.js"></script>
 </head>
 <body>
   <h1>Background_Sync_API Test</h1>
 </body>
</html>