[ServiceWorker] Update formatting for tests.

LayoutTests/http/tests/serviceworker/resources/cache-add-worker.js

 importScripts('worker-testharness.js');
 importScripts('/resources/testharness-helpers.js');
 
 cache_test(function(cache) {
     return assert_promise_rejects(
       cache.add(),
       new TypeError(),
       'Cache.add should throw a TypeError when no arguments are given.');
   }, 'Cache.add called with no arguments');
 
@@ skipping 84 matching lines @@
       'Cache.addAll should throw TypeError for an undefined argument.');
   }, 'Cache.addAll with a mix of valid and undefined arguments');
 
 cache_test(function(cache) {
     // Assumes the existence of simple.txt and blank.html in the same directory
     // as this test script.
     var urls = ['simple.txt', self.location.href, 'blank.html'];
     return cache.addAll(urls)
       .then(function(result) {
           assert_equals(result, undefined,
-                        'Cache.addAll should resolve with undefined on success.');
+                        'Cache.addAll should resolve with undefined on ' +
+                        'success.');
         });
   }, 'Cache.addAll with string URL arguments');
 
 cache_test(function(cache) {
     // Assumes the existence of simple.txt and blank.html in the same directory
     // as this test script.
     var urls = ['simple.txt', self.location.href, 'blank.html'];
     var requests = urls.map(function(url) {
         return new Request(url);
       });
@@ skipping 21 matching lines @@
   }, 'Cache.addAll with a mix of succeeding and failing requests');
 
 cache_test(function(cache) {
     var request = new Request('simple.txt');
     return assert_promise_rejects(
       cache.addAll([request, request]),
       new TypeError(),
       'Cache.addAll should throw TypeError if the same request is added ' +
       'twice.');
   }, 'Cache.addAll called with the same Request object specified twice');