Polished update screen.

chrome/browser/resources/chromeos/login/oobe.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 the Out of the box experience (OOBE) flow,
  * sign in and lock screens.
  */
 
 html,
 body {
@@ skipping 693 matching lines @@
 
 .step-extra-controls > *:not(:first-child) {
   -webkit-margin-before: 7px;
 }
 
 html[dir=rtl] .step-extra-controls {
   left: auto;
   right: 49px;
 }
 
-#update-screen-curtain p {
-  text-align: center;
+.throbber {
+  -webkit-animation: throbber-animation 1s steps(36) infinite;
+  -webkit-margin-before: 2px;
+  -webkit-margin-end: 4px;
+  background-image: url(chrome://theme/IDR_CROS_DEFAULT_THROBBER);
+  display: inline-block;
+  height: 16px;
+  width: 16px;
+}
+
+@-webkit-keyframes throbber-animation {
+  from {
+    background-position: 0;
+  }
+  to {
+    background-position: -576px;
+  }
 }
 
 #update #update-screen-curtain {
   -webkit-box-align: start;
   -webkit-box-pack: center;
 }
 
 #update #update-checking-progress {
   -webkit-box-align: start;
   -webkit-box-pack: center;
   color: #9c9c9c;
   display: -webkit-box;
 }
 
 #update #update-screen-curtain {
-  margin: 45px 45px;
+  margin: 45px 35px;
 }
 
 #update-screen-main {
-  margin: 45px 45px;
+  margin: 45px 35px;
   min-height: 114px;
   text-align: center;
 }
 
-#update #update-checking-ellipsis {
-  width: 16px;
-}
-
-html[dir=ltr] #update #update-checking-ellipsis {
-  text-align: left;
-}
-
-html[dir=rtl] #update #update-checking-ellipsis {
-  text-align: right;
-}
-
 #update #update-cancel-hint {
   -webkit-margin-before: 15px;
   -webkit-margin-start: 45px;
   color: rgb(170, 0, 0);
   position: absolute;
 }
 
 #update #update-upper-label {
   -webkit-margin-after: 4px;
 }
 
 #update #checking-updates-label {
-  -webkit-margin-after: 34px;
+  -webkit-margin-after: 90px;
 }
 
 #update #update-bottom-label {
   -webkit-margin-after: 4px;
   -webkit-margin-before: 4px;
   text-align: left;
 }
 
 #update progress {
   -webkit-margin-after: 4px;
@@ skipping 345 matching lines @@
 }
 
 .background-initial {
   opacity: 0;
 }
 
 .background-final {
   opacity: 1;
 }