Begin to enable extension APIs in Extension Service Worker.

chrome/test/data/extensions/api_test/service_worker/tabs_create/page.js

-// Copyright 2015 The Chromium Authors. All rights reserved.
+// Copyright 2016 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) {
-      if (e.data == 'Pong from version 1') {
+      if (e.data == 'chrome.tabs.create callback') {
         resolve(e.data);
       } else {
-        reject(e.data);  // Fail fast.
+        reject(e.data);
       }
     };
-    sw.postMessage('ping', [channel.port2]);
+    sw.postMessage('createTab', [channel.port2]);
   }).catch(function(err) {
     reject(err);
   });
 });
 
-serviceWorkerPromise.then(function(message) {
-  chrome.test.sendMessage(message);
-}).catch(function(err) {
-  chrome.test.sendMessage('FAILURE');
-});
+window.runServiceWorker = function() {
+  serviceWorkerPromise.then(function(message) {
+    window.domAutomationController.send(message);
+  }).catch(function(err) {
+    window.domAutomationController.send('FAILURE');
+  });
+};