Fix misplacement of signin overlay and critical update message banner

ui/login/md_screen_container.css

 /* Copyright 2014 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.
  */
 
 #outer-container {
   -webkit-box-align: center;
   -webkit-box-pack: center;
   bottom: 57px;  /* Leave space for the header bar */
   display: -webkit-box;
@@ skipping 74 matching lines @@
 #oobe.debugging #inner-container,
 #oobe.enrollment #inner-container,
 #oobe:not([md-mode]).eula #inner-container,
 #oobe.fatal-error #inner-container,
 #oobe.gaia-signin #inner-container,
 #oobe.hid-detection #inner-container,
 #oobe.kiosk-enable #inner-container,
 #oobe.oauth-enrollment #inner-container,
 #oobe.password-changed #inner-container,
 #oobe.ad-password-change #inner-container,
-#oobe.reset #inner-container,
+#oobe:not([md-mode]).reset #inner-container,

[jdufault, 2017/06/15 17:52:09]

This file is md-only, can this be removed entirely?

[Wenzhao (Colin) Zang, 2017/06/15 18:40:21]

Yes, all 'not([md-mode])' are removed.

 #oobe.supervised-user-creation #inner-container,
 #oobe.supervised-user-creation-dialog #inner-container,
 #oobe.terms-of-service #inner-container,
 #oobe.arc-tos #inner-container,
 #oobe.update #inner-container,
 #oobe.user-image #inner-container,
 #oobe.wrong-hwid #inner-container,
 #oobe.unrecoverable-cryptohome-error #inner-container {
   background: white;
   box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.3),
@@ skipping 139 matching lines @@
   line-height: 31px;
   text-transform: lowercase;
   width: 23em;
 }
 
 .header-section::before {
   /* Divider in header between product name and title,
    * like "[Product name] > [step header]". */
   content: '\00A0\203A\00A0\00A0';
 }