Update signout icon and more_settings icon on the md shelf

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;
   bottom: 0;
   left: 0;
   padding-bottom: 6px;
   position: absolute;
@@ skipping 75 matching lines @@
 
 html[dir=rtl] .header-bar-item {
   background-position: right center;
 }
 
 #login-header-bar #shutdown-button-text,
 #login-header-bar #restart-button-text,
 #login-header-bar #add-user-button-text,
 #login-header-bar #guest-user-button-text,
 #login-header-bar #more-settings-button-text,
-#login-header-bar #cancel-multiple-sign-in-button-text {
+#login-header-bar #cancel-multiple-sign-in-button-text,
+#login-header-bar #sign-out-user-button-text {
   -webkit-padding-start: 28px;
   background-position: left center;
   background-repeat: no-repeat;
   background-size: 20px;
 }
 
 html[dir=rtl] #login-header-bar #shutdown-button-text,
 html[dir=rtl] #login-header-bar #restart-button-text,
 html[dir=rtl] #login-header-bar #add-user-button-text,
 html[dir=rtl] #login-header-bar #more-settings-button-text,
 html[dir=rtl] #login-header-bar #guest-user-button-text,
-html[dir=rtl] #login-header-bar #cancel-multiple-sign-in-button-text {
+html[dir=rtl] #login-header-bar #cancel-multiple-sign-in-button-text,
+html[dir=rtl] #login-header-bar #sign-out-user-button-text {
   background-position: right center;
 }
 
 #login-header-bar #shutdown-button,
 #login-header-bar #restart-button,
 #login-header-bar #add-user-button,
 #login-header-bar #guest-user-button,
 #login-header-bar #more-settings-button,
 #login-header-bar #cancel-multiple-sign-in-button {
   padding: 0 14px;
@@ skipping 10 matching lines @@
       url(images/2x/shutdown.svg) 2x );
 }
 
 #login-header-bar #add-user-button-text {
   background-image: -webkit-image-set(
       url(images/1x/add-person.svg) 1x,
       url(images/2x/add-person.svg) 2x );
 }
 
 #login-header-bar #more-settings-button-text {
-  background-image: url(chrome://theme/IDR_ICON_MORE_VERT_WHITE);
+  background-image: -webkit-image-set(
+      url(images/1x/more-settings.svg) 1x,
+      url(images/2x/more-settings.svg) 2x );
 }
 
 #login-header-bar #guest-user-button-text {
   background-image: -webkit-image-set(
       url(images/1x/browse-as-guest.svg) 1x,
       url(images/2x/browse-as-guest.svg) 2x );
 }
 
 #login-header-bar #cancel-multiple-sign-in-button-text {
   /* TODO(dzhioev): replace with appropriate image when possible. */
   background-image: url(chrome://theme/IDR_PANEL_CLOSE);
 }
 
+#login-header-bar #sign-out-user-button-text {
+  background-image: -webkit-image-set(
+      url(images/1x/signout.svg) 1x,
+      url(images/2x/signout.svg) 2x );
+}
+
 .button-restricted {
   border: 1px solid transparent;
   color: white !important;
   opacity: 0.4 !important;
 }