diff -r 000000000000 -r 6474c204b198 toolkit/mozapps/extensions/content/xpinstallConfirm.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/mozapps/extensions/content/xpinstallConfirm.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,170 @@
+// -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+var XPInstallConfirm = {};
+
+XPInstallConfirm.init = function XPInstallConfirm_init()
+{
+  var _installCountdown;
+  var _installCountdownInterval;
+  var _focused;
+  var _timeout;
+
+  // Default to cancelling the install when the window unloads
+  XPInstallConfirm._installOK = false;
+
+  var bundle = document.getElementById("xpinstallConfirmStrings");
+
+  let args = window.arguments[0].wrappedJSObject;
+
+  var _installCountdownLength = 5;
+  try {
+    var prefs = Components.classes["@mozilla.org/preferences-service;1"]
+                          .getService(Components.interfaces.nsIPrefBranch);
+    var delay_in_milliseconds = prefs.getIntPref("security.dialog_enable_delay");
+    _installCountdownLength = Math.round(delay_in_milliseconds / 500);
+  } catch (ex) { }
+  
+  var itemList = document.getElementById("itemList");
+  
+  var numItemsToInstall = args.installs.length;
+  for (let install of args.installs) {
+    var installItem = document.createElement("installitem");
+    itemList.appendChild(installItem);
+
+    installItem.name = install.addon.name;
+    installItem.url = install.sourceURI.spec;
+    var icon = install.iconURL;
+    if (icon)
+      installItem.icon = icon;
+    var type = install.type;
+    if (type)
+      installItem.type = type;
+    if (install.certName) {
+      installItem.cert = bundle.getFormattedString("signed", [install.certName]);
+    }
+    else {
+      installItem.cert = bundle.getString("unverified");
+    }
+    installItem.signed = install.certName ? "true" : "false";
+  }
+  
+  var introString = bundle.getString("itemWarnIntroSingle");
+  if (numItemsToInstall > 4)
+    introString = bundle.getFormattedString("itemWarnIntroMultiple", [numItemsToInstall]);
+  var textNode = document.createTextNode(introString);
+  var introNode = document.getElementById("itemWarningIntro");
+  while (introNode.hasChildNodes())
+    introNode.removeChild(introNode.firstChild);
+  introNode.appendChild(textNode);
+  
+  var okButton = document.documentElement.getButton("accept");
+  okButton.focus();
+
+  function okButtonCountdown() {
+    _installCountdown -= 1;
+
+    if (_installCountdown < 1) {
+      okButton.label = bundle.getString("installButtonLabel");
+      okButton.disabled = false;
+      clearInterval(_installCountdownInterval);
+    }
+    else
+      okButton.label = bundle.getFormattedString("installButtonDisabledLabel", [_installCountdown]);
+  }
+
+  function myfocus() {
+    // Clear the timeout if it exists so only the last one will be used.
+    if (_timeout)
+      clearTimeout(_timeout);
+
+    // Use setTimeout since the last focus or blur event to fire is the one we
+    // want
+    _timeout = setTimeout(setWidgetsAfterFocus, 0);
+  }
+
+  function setWidgetsAfterFocus() {
+    if (_focused)
+      return;
+
+    _installCountdown = _installCountdownLength;
+    _installCountdownInterval = setInterval(okButtonCountdown, 500);
+    okButton.label = bundle.getFormattedString("installButtonDisabledLabel", [_installCountdown]);
+    _focused = true;
+  }
+
+  function myblur() {
+    // Clear the timeout if it exists so only the last one will be used.
+    if (_timeout)
+      clearTimeout(_timeout);
+
+    // Use setTimeout since the last focus or blur event to fire is the one we
+    // want
+    _timeout = setTimeout(setWidgetsAfterBlur, 0);
+  }
+
+  function setWidgetsAfterBlur() {
+    if (!_focused)
+      return;
+
+    // Set _installCountdown to the inital value set in setWidgetsAfterFocus
+    // plus 1 so when the window is focused there is immediate ui feedback.
+    _installCountdown = _installCountdownLength + 1;
+    okButton.label = bundle.getFormattedString("installButtonDisabledLabel", [_installCountdown]);
+    okButton.disabled = true;
+    clearInterval(_installCountdownInterval);
+    _focused = false;
+  }
+
+  function myUnload() {
+    if (_installCountdownLength > 0) {
+      document.removeEventListener("focus", myfocus, true);
+      document.removeEventListener("blur", myblur, true);
+    }
+    window.removeEventListener("unload", myUnload, false);
+
+    // Now perform the desired action - either install the
+    // addons or cancel the installations
+    if (XPInstallConfirm._installOK) {
+      for (let install of args.installs)
+        install.install();
+    }
+    else {
+      for (let install of args.installs)
+        install.cancel();
+    }
+  }
+
+  window.addEventListener("unload", myUnload, false);
+
+  if (_installCountdownLength > 0) {
+    document.addEventListener("focus", myfocus, true);
+    document.addEventListener("blur", myblur, true);
+
+    okButton.disabled = true;
+    setWidgetsAfterFocus();
+  }
+  else
+    okButton.label = bundle.getString("installButtonLabel");
+}
+
+XPInstallConfirm.onOK = function XPInstallConfirm_onOk()
+{
+  Components.classes["@mozilla.org/base/telemetry;1"].
+    getService(Components.interfaces.nsITelemetry).
+    getHistogramById("SECURITY_UI").
+    add(Components.interfaces.nsISecurityUITelemetry.WARNING_CONFIRM_ADDON_INSTALL_CLICK_THROUGH);
+  // Perform the install or cancel after the window has unloaded
+  XPInstallConfirm._installOK = true;
+  return true;
+}
+
+XPInstallConfirm.onCancel = function XPInstallConfirm_onCancel()
+{
+  // Perform the install or cancel after the window has unloaded
+  XPInstallConfirm._installOK = false;
+  return true;
+}