[ServiceWorker] Remove the test for the rejected result of FetchEvent from fetch-event.html

LayoutTests/http/tests/serviceworker/resources/fetch-event-test-worker.js

 function handleString(event) {
   event.respondWith(new Response('Test string'));
 }
 
 function handleBlob(event) {
   event.respondWith(new Response(new Blob(['Test blob'])));
 }
 
 function handleReferrer(event) {
   event.respondWith(new Response(new Blob(
     ['Referrer: ' + event.request.referrer])));
 }
 
 function handleNullBody(event) {
   event.respondWith(new Response(null));
 }
 
-function handleReject(event) {
-  event.respondWith(new Promise(function(resolve, reject) {
-      reject('rejected!');
-    }));
-}
-
 function handleFetch(event) {
   event.respondWith(fetch('other.html'));
 }
 
 function handleFormPost(event) {
   event.respondWith(new Promise(function(resolve) {
       event.request.text()
         .then(function(result) {
             resolve(new Response(event.request.method + ':' + result));
           })
@@ skipping 14 matching lines @@
 }
 
 self.addEventListener('fetch', function(event) {
     var url = event.request.url;
     var handlers = [
       { pattern: '?string', fn: handleString },
       { pattern: '?blob', fn: handleBlob },
       { pattern: '?referrer', fn: handleReferrer },
       { pattern: '?ignore', fn: function() {} },
       { pattern: '?null', fn: handleNullBody },
-      { pattern: '?reject', fn: handleReject },
       { pattern: '?fetch', fn: handleFetch },
       { pattern: '?form-post', fn: handleFormPost },
       { pattern: '?multiple-respond-with', fn: handleMultipleRespondWith }
     ];
 
     var handler = null;
     for (var i = 0; i < handlers.length; ++i) {
       if (url.indexOf(handlers[i].pattern) != -1) {
         handler = handlers[i];
         break;
       }
     }
 
     if (handler) {
       handler.fn(event);
     } else {
       event.respondWith(new Response(new Blob(
         ['Service Worker got an unexpected request: ' + url])));
     }
   });