cros: Update SAML flow.

chrome/browser/resources/chromeos/login/screen_fatal_error.js

 // Copyright 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 A simple message box screen implementation.
  */
 
-login.createScreen('MessageBoxScreen', 'message-box', function() { return {
+login.createScreen('FatalErrorScreen', 'fatal-error', function() { return {
     EXTERNAL_API: [
       'show'
     ],
 
     /**
      * Callback to run when the screen is dismissed.
      * @type {function()}
      */
     callback_: null,
 
     /**
-     * Ok button of the message box.
-     * @type {HTMLButtonElement}
-     */
-    okButton_: null,
-
-    /**
      * Saved hidden status of 'progress-dots'.
      * @type {boolean}
      */
     savedProgressDotsHidden_: null,
 
-    /**
-     * Screen controls in bottom strip.
-     * @type {Array.<HTMLButtonElement>} Buttons to be put in the bottom strip.
-     */
-    get buttons() {
-      var buttons = [];
-
-      this.okButton_ = this.ownerDocument.createElement('button');
-      this.okButton_.addEventListener('click', this.onDismiss_.bind(this));
-      buttons.push(this.okButton_);
-
-      return buttons;
+    /** @override */
+    decorate: function() {
+      $('fatal-error-dismiss-button').addEventListener(
+          'click', this.onDismiss_.bind(this));
     },
 
     get defaultControl() {
-      return this.okButton_;
+      return $('fatal-error-dismiss-button');
     },
 
     /**
      * Invoked when user clicks on the ok button.
      */
     onDismiss_: function() {
       this.callback_();
       $('progress-dots').hidden = this.savedProgressDotsHidden_;
     },
 
     /**
      * Shows the no password warning screen.
-     * @param {string} title Title string of the message box.
-     * @param {string} message Body text of the message box.
-     * @param {string} okLabel Label text for the okay button.
      * @param {function()} callback The callback to be invoked when the
      *     screen is dismissed.
      */
-    show: function(title, message, okLabel, callback) {
-      $('message-box-title').textContent = title;
-      $('message-box-body').textContent = message;
-      this.okButton_.textContent = okLabel;
+    show: function(callback) {
+      Oobe.getInstance().headerHidden = true;

[Nikita (slow), 2014/02/06 05:08:25]

nit: When does this header will be restored if we return back to the user pods?

https://code.google.com/p/chromium/codesearch#search/&q=Oobe.getInstance%5C(%...

[xiyuan, 2014/02/06 05:46:05]

Right now it is okay because we always go back to Gaia after this error and Gaia
shows header. But you are right, we probably should restore this in onDismiss in
case the callback is changed in the future. I will do that in a follow up CL.

       this.callback_ = callback;
 
-      Oobe.showScreen({id: SCREEN_MESSAGE_BOX});
+      Oobe.showScreen({id: SCREEN_FATAL_ERROR});
 
       this.savedProgressDotsHidden_ = $('progress-dots').hidden;
       $('progress-dots').hidden = true;
     }
   };
 });