Represent kiosk apps as user pods instead of menu items.

chrome/browser/resources/chromeos/login/user_pod_row.css

 /* Copyright (c) 2012 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.
  *
  * This is the stylesheet used by user pods row of account picker UI.
  */
 
 podrow {
   /* Temporarily disabled because animation interferes with updating screen's
    size. */
@@ skipping 156 matching lines @@
   height: 40px;
   outline: none;
   padding: 4px 6px;
   width: 100%;
 }
 
 .pod.need-password.focused .password-area {
   display: -webkit-box;
 }
 
-.pod .signin-button {
+.pod .signin-button,
+.pod .launch-app-button {
   box-sizing: border-box;
   display: inline-block;
   height: 26px;
   margin: 6px 0;
   max-width: 100%;
   min-width: 72px !important;
   padding: 4px 8px;
 }
 
-.pod:not(.focused) .signin-button {
+.pod:not(.focused) .signin-button,
+.pod:not(.focused) .launch-app-button  {
   display: none;
 }
 
 .pod .capslock-hint {
   bottom: 13px;
   cursor: text;
   position: absolute;
   right: 6px;
   visibility: hidden;
   z-index: 1;
@@ skipping 363 matching lines @@
 .pod.public-account.expanded .name,
 .pod.public-account.expanded .learn-more {
   display: none;
 }
 
 .pod.public-account.expanded .side-pane-divider,
 .pod.public-account.expanded .side-pane-container,
 .pod.public-account.animating .side-pane-container {
   visibility: inherit;
 }