[Extension ServiceWorkers] Allow service worker registration

chrome/test/data/extensions/api_test/service_worker/fetch/sw.js

Index: chrome/test/data/extensions/api_test/service_worker/fetch/sw.js
diff --git a/chrome/test/data/extensions/api_test/service_worker/register/sw.js b/chrome/test/data/extensions/api_test/service_worker/fetch/sw.js
similarity index 61%
copy from chrome/test/data/extensions/api_test/service_worker/register/sw.js
copy to chrome/test/data/extensions/api_test/service_worker/fetch/sw.js
index 78cf16c57f711facbf0d5e33977fb4d1fcb31fbf..d2c5fbdcade4ce5b268c34375dac1c026942c5ba 100644
--- a/chrome/test/data/extensions/api_test/service_worker/register/sw.js
+++ b/chrome/test/data/extensions/api_test/service_worker/fetch/sw.js
@@ -2,4 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-console.log("Hello from the service worker");
+self.addEventListener('fetch', function(event) {
+  event.respondWith(new Response('Caught a fetch!'));
+});