Changing manifest to v2 extension samples

chrome/common/extensions/docs/examples/api/i18n/getMessage/popup.js

+function setChildTextNode(elementId, text) {
+  document.getElementById(elementId).innerText = text;
+}
+
+function init() {
+  setChildTextNode('languageSpan', chrome.i18n.getMessage("click_here"));
+}
+
+function getAcceptLanguages() {
+  chrome.i18n.getAcceptLanguages(function(languageList) {
+    var languages = languageList.join(",");
+    setChildTextNode('languageSpan',
+        chrome.i18n.getMessage("chrome_accept_languages", languages));
+  })
+}
+
+document.addEventListener('DOMContentLoaded', function() {
+  document.querySelector('#accept_lang').addEventListener(
+      'click', getAcceptLanguages);
+});