MD Settings: Restore focus after exiting various subpages.

chrome/browser/resources/settings/languages_page/languages_page.html

 <link rel="import" href="chrome://resources/html/action_link.html">
 <link rel="import" href="chrome://resources/html/action_link_css.html">
 <link rel="import" href="chrome://resources/html/assert.html">
 <link rel="import" href="chrome://resources/html/cr.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-collapse/iron-collapse.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-checkbox/paper-checkbox.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
@@ skipping 53 matching lines @@
       }
 
       #uiLanguageItem:focus,
       #offerTranslations:focus {
         background-color: transparent;
       }
     </style>
     <settings-languages languages="{{languages}}" prefs="{{prefs}}"
         language-helper="{{languageHelper}}">
     </settings-languages>
-    <settings-animated-pages id="pages" section="languages">
+    <settings-animated-pages id="pages" section="languages"
+        focus-config="[[focusConfig_]]">
       <neon-animatable route-path="default">
         <div class$="settings-box first [[getLanguageListTwoLine_()]]"
             actionable on-tap="toggleExpandButton_">
           <div class="start">
             <div>$i18n{languagesListTitle}</div>
 <if expr="chromeos or is_win">
             <div class="secondary">
               [[getProspectiveUILanguageName_(languages.prospectiveUILanguage)]]
             </div>
 </if>
@@ skipping 220 matching lines @@
 </if>
     </settings-animated-pages>
     <template is="dom-if" if="[[showAddLanguagesDialog_]]" restamp>
       <settings-add-languages-dialog languages="{{languages}}"
           language-helper="[[languageHelper]]">
       </settings-add-languages-dialog>
     </template>
   </template>
   <script src="languages_page.js"></script>
 </dom-module>