Prevent unexpected pods sliding on start screen.

ui/login/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;
   -webkit-perspective: 1px; /* Workaround, see http://crbug.com/360567 */
   bottom: 51px;  /* Leave space for the header bar */
@@ skipping 66 matching lines @@
 }
 
 #oobe.error-message #inner-container,
 #oobe.tpm-error-message #inner-container {
   box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.3),
               0 4px 23px 5px rgba(0, 0, 0, 0.2),
               0 2px 6px rgba(0, 0, 0, 0.15);
 
 }
 
-#oobe.account-picker.flying-pods #inner-container {
-  -webkit-transition: width 180ms ease,
-                      height 180ms ease;
-}
-
 /* Only play this animation when 'down' class is removed. */
 .oobe-display #inner-container:not(.down) {
   -webkit-transition: -webkit-transform 200ms ease-in-out;
 }
 
 .oobe-display #inner-container.down {
   -webkit-transform: translateY(50px) rotateX(-2.5deg);
 }
 
 #step-logo {
@@ skipping 106 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';
 }