Spoken text for [...] button on login screen

chrome/browser/resources/chromeos/login/header_bar.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.
  */
 
 #login-header-bar {
   -webkit-padding-start: 15px;
   border-bottom: 3px solid black;
   bottom: 0;
   left: 0;
@@ skipping 109 matching lines @@
 #login-header-bar #restart-button {
   background-image: url(chrome://theme/IDR_ICON_POWER_WHITE);
 }
 
 #login-header-bar #add-user-button {
   background-image: url(chrome://theme/IDR_ICON_ADD_USER_WHITE);
 }
 
 #login-header-bar #more-settings-button {
   background-image: url(chrome://theme/IDR_ICON_MORE_VERT_WHITE);
+  font-size: 0;

[Greg Levin, 2015/05/16 00:57:01]

This seemed like a simple way to allow a i18n-content label on the button, but
not display the actual text.  Is there a preferred way of doing this?

 }
 
 #login-header-bar #guest-user-button {
   background-image: url(chrome://theme/IDR_ICON_GUEST_WHITE);
 }
 
 #login-header-bar #cancel-multiple-sign-in-button {
   /* TODO(dzhioev): replace with appropriate image when possible. */
   background-image: url(chrome://theme/IDR_PANEL_CLOSE);
 }
 
 .button-restricted {
   border: 1px solid transparent;
   color: white !important;
   opacity: 0.4 !important;
 }