Changing manifest to v2 extension samples

chrome/common/extensions/docs/examples/apps/background-simple/index.js

+// Copyright (c) 2012 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.
+
+// Check for support
+if (window.chrome && window.chrome.app && window.chrome.app.isInstalled) {
+  document.getElementById('supported').className = '';
+} else {
+  document.getElementById('unsupported').className = '';
+}
+var bgWinUrl = "background.html#yay";
+var bgWinName = "bgNotifier";
+
+function openBackgroundWindow() {
+  window.open(bgWinUrl, bgWinName, "background");
+}
+
+function closeBackgroundWindow() {
+  var w = window.open(bgWinUrl, bgWinName, "background");
+  w.close();
+}
+
+document.addEventListener('DOMContentLoaded', function() {
+  document.querySelector('#openBackgroundWindow').addEventListener(
+    'click', openBackgroundWindow);
+  document.querySelector('#closeBackgroundWindow').addEventListener(
+    'click', closeBackgroundWindow);
+});