Translate: browser test to verify whole translate process

chrome/test/data/translate/pseudo_main.js

+div_log = function (message) {
+  var div = document.getElementById('log');
+  var element = document.createElement('pre');
+  element.innerText = message;
+  div.appendChild(element);
+}
+if (typeof world != 'undefined') {
+  div_log('v8 isolation doesn\'t work');
+  document.title = 'FAIL';
+  return;
+}
+div_log('The first script pseudo_main.js is loaded');
+div_log('Loading the second script pseudo_element_main.js ...');
+var head = document.getElementsByTagName('head')[0];
+var script = document.createElement('script');
+script.src = element_main_script_url;
+head.appendChild(script);