Upstream service worker navigation tests to WPT

third_party/WebKit/LayoutTests/external/wpt/service-workers/service-worker/resources/navigation-redirect-body-worker.js

 self.addEventListener('fetch', function(event) {
     event.respondWith(
         fetch(event.request)
           .then(
               function(response) {
                 return response;
               },
               function(error) {
                 return new Response('Error:' + error);
               }));
   });