Changing manifest to v2 extension samples

chrome/common/extensions/docs/examples/api/infobars/sandwichbar/infobar.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.
+
+// Obtain the count of sandwiches from the page URL.
+var count = window.location.hash.substring(1);
+if (count) {
+  // Replace the placeholder text with the actual count.
+  var domcount = document.querySelector('#count');
+  domcount.innerText = count;
+}