Add a test to cover service worker update codepath when extension is updated

chrome/test/data/extensions/api_test/service_worker/update/v2/background.js

Index: chrome/test/data/extensions/api_test/service_worker/update/v2/background.js
diff --git a/chrome/test/data/extensions/api_test/service_worker/update/v2/background.js b/chrome/test/data/extensions/api_test/service_worker/update/v2/background.js
new file mode 100644
index 0000000000000000000000000000000000000000..9d5d43d2633daa6f1ed70530c11a919f2d02c794
--- /dev/null
+++ b/chrome/test/data/extensions/api_test/service_worker/update/v2/background.js
@@ -0,0 +1,29 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var serviceWorkerPromise = new Promise(function(resolve, reject) {
+  navigator.serviceWorker.register('sw.js').then(function() {
+    return navigator.serviceWorker.ready;
+  }).then(function(registration) {
+    var sw = registration.active;
+    var channel = new MessageChannel();
+    channel.port1.onmessage = function(e) {
+      resolve(e.data);
+    };
+    sw.postMessage('ping', [channel.port2]);
+  }).catch(function(err) {
+    reject(err);
+  });
+});
+
+var testPromise = new Promise(function(resolve) {
+  window.testResolver = resolve;
+});
+
+Promise.all([serviceWorkerPromise, testPromise]).then(function(messages) {
+  window.domAutomationController.send(
+      String(messages[0] == 'Pong from version 2'));
+}).catch(function(err) {
+  window.domAutomationController.send('false');
+});