Import w3c tests for the service workers

third_party/WebKit/LayoutTests/imported/wpt/service-workers/service-worker/ServiceWorkerGlobalScope/resources/update-worker.js

-<?php
-// update() does not bypass cache so set the max-age to 0 such that update()
-// can find a new version in the network.
-header('Cache-Control: max-age=0');
-
-// Return a different script for each access.
-header('Content-Type:application/javascript');
-echo '// ' . microtime();
-?>
-
-importScripts('../../resources/test-helpers.js');
+importScripts('../../resources/test-helpers.sub.js');
 importScripts('../../resources/worker-testharness.js');
 
 var events_seen = [];
 
 self.registration.addEventListener('updatefound', function() {
     events_seen.push('updatefound');
   });
 
 self.addEventListener('activate', function(e) {
     events_seen.push('activate');
   });
 
 self.addEventListener('fetch', function(e) {
     events_seen.push('fetch');
     e.respondWith(new Response(events_seen));
   });
 
 self.addEventListener('message', function(e) {
     events_seen.push('message');
     self.registration.update();
   });
 
 // update() during the script evaluation should be ignored.
 self.registration.update();