Implement the auto-logout on idle feature for Kiosk mode.

chrome/browser/resources/chromeos/idle_logout_dialog.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.
+
+var localStrings;
+
+// Timer that will check and update the countdown every second.
+var countdownTimer;
+// Time at which we should logout the user unless we've been closed.
+var logoutTime; // ms
+
+/**
+ * Gets time since epoch in miliseconds.
+ */
+function getMillisecondsSinceEpoch() {
+  var time = new Date();
+  return time.getTime();
+}
+
+/**
+ * Decrements the countdown timer and updates the display on the dialog.
+ */
+function decrementTimer() {
+  var currentTime = getMillisecondsSinceEpoch();

[arv (Not doing code reviews), 2012/03/02 02:26:20]

replace with Date.now()

[rkc, 2012/03/02 03:03:21]

Done.

+  if (logoutTime > currentTime) {
+    secondsToRestart = Math.round((logoutTime - currentTime) / 1000);
+    $('warning').innerHTML = localStrings.getStringF('warning',
+                                                     secondsToRestart);
+  } else {
+    clearInterval(countdownTimer);
+    chrome.send('requestLogout');
+  }
+}
+
+/**
+ * Starts the countdown to logout.
+ */
+function startCountdown(seconds) {
+  logoutTime = getMillisecondsSinceEpoch() + (seconds * 1000);
+  $('warning').innerHTML = localStrings.getStringF('warning',
+                                                   seconds);
+  countdownTimer = setInterval(decrementTimer, 1000);
+}
+
+/**
+ * Inserts translated strings on loading.
+ */
+function initialize() {
+  localStrings = new LocalStrings();
+
+  i18nTemplate.process(document, templateData);
+  chrome.send('requestCountdown');
+}
+
+document.addEventListener('DOMContentLoaded', initialize);