Refactor kiosk app launch to be part of login screen UI flow.

chrome/browser/resources/chromeos/app_launch/app_launch.js

-// Copyright (c) 2013 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.
-
-/**
- * @fileoverview App install/launch splash screen.
- */
-
-/**
- * Initializes the click handler.
- */
-initialize = function() {
-  var params = parseQueryParams(window.location);
-  var appId = params['app'] || '';
-
-  chrome.send('initialize', [appId]);
-
-  $('shortcut-info').hidden = !loadTimeData.getBoolean('shortcutEnabled');
-  $('page').style.opacity = 1;
-  window.webkitRequestAnimationFrame(function() {});
-};
-
-updateApp = function(app) {
-  $('header').textContent = app.name;
-  $('header').style.backgroundImage = 'url(' + app.iconURL + ')';
-};
-
-updateMessage = function(message) {
-  $('launch-text').textContent = message;
-};
-
-disableTextSelectAndDrag();
-document.addEventListener('DOMContentLoaded', initialize);