chromium/chrome/test/data/extensions/api_test/app_process/test.html

<script>
// Copyright 2010 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

var origin = "http://localhost:1337/extensions/api_test/app_process/";
var url1 = origin + "path1/empty.html";
var url2 = origin + "path2/empty.html";
var url3 = origin + "path3/empty.html";

// Create 3 tabs. The first 2 should be grouped into the same app process.
chrome.tabs.create({url: url1}, function() {
  chrome.tabs.create({url: url2}, function() {
    chrome.tabs.create({url: url3}, function() {
      chrome.test.notifyPass();
    });
  });
});

function testWindowOpen() {
  window.open(url1);
  window.open(url2);
  window.open(url3);
}
</script>