Updates the hotword settings page according to newest mocks.

chrome/browser/resources/options/browser_options.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. */
 
 #change-home-page-section {
   margin-left: 30px;
 }
 
 #home-page-url {
   display: inline-block;
@@ skipping 168 matching lines @@
  * of pages that depend on it.
  * TODO(kevers): Rivisit padding rules. */
 #default-search-engine {
   padding-bottom: 0;
 }
 
 .hotword-settings {
   -webkit-margin-start: 22px;
 }
 
+.hotword-description {
+  -webkit-margin-start: 1.8em;
+  color: gray;
+}
+
+.hotword-learn-more-link {
+  -webkit-padding-start: 8px;
+}
+
 /* Internet settings */
 
 #network-settings {
   position: relative;
 }
 
 #network-list {
   min-height: 0;
   width: 320px;
 }
@@ skipping 283 matching lines @@
 
 #about-button {
   -webkit-margin-end: 30px;
 }
 
 /* An input that has no function except to take up the same amount of space as
  * a checkbox. */
 .spacer-checkbox {
   visibility: hidden;
 }