MD Settings: Restore focus after exiting various subpages.

chrome/browser/resources/settings/appearance_page/appearance_page.html

 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/md_select_css.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="appearance_browser_proxy.html">
 <link rel="import" href="../controls/controlled_radio_button.html">
 <link rel="import" href="../controls/extension_controlled_indicator.html">
@@ skipping 18 matching lines @@
       #custom-input {
         margin-bottom: 1rem;
       }
 
       #customHomePage {
         --paper-input-container: {
           width: 200px;
         };
       }
     </style>
-    <settings-animated-pages id="pages" section="appearance">
+    <settings-animated-pages id="pages" section="appearance"
+        focus-config="[[focusConfig_]]">
       <neon-animatable route-path="default">
 <if expr="chromeos">
         <div class="settings-box first two-line" id="wallpaperButton"
             on-tap="openWallpaperManager_" actionable
             hidden="[[!pageVisibility.setWallpaper]]">
           <div class="start">
             $i18n{setWallpaper}
             <div class="secondary" id="wallpaperSecondary">
               $i18n{openWallpaperApp}
             </div>
@@ skipping 143 matching lines @@
             associated-control="[[$$('#customize-fonts-subpage-trigger')]]"
             page-title="$i18n{customizeFonts}">
           <settings-appearance-fonts-page prefs="{{prefs}}">
           </settings-appearance-fonts-page>
         </settings-subpage>
       </template>
     </settings-animated-pages>
   </template>
   <script src="appearance_page.js"></script>
 </dom-module>