MD Settings: Restore focus after exiting various subpages.

chrome/browser/resources/settings/a11y_page/a11y_page.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview
  * 'settings-a11y-page' is the small section of advanced settings with
  * a link to the web store accessibility page on most platforms, and
  * a subpage with lots of other settings on Chrome OS.
  */
 Polymer({
   is: 'settings-a11y-page',
 
   properties: {
     /**
      * The current active route.
      */
     currentRoute: {
       type: Object,
       notify: true,
     },
 
     /**
      * Preferences state.
      */
     prefs: {
       type: Object,
       notify: true,
     },
+
+    /** @private {!Map<string, string>} */
+    focusConfig_: {
+      type: Object,
+      value: function() {
+        var map = new Map();
+// <if expr="chromeos">
+        map.set(
+            settings.Route.MANAGE_ACCESSIBILITY.path,
+            '#subpage-trigger .subpage-arrow');
+// </if>
+        return map;
+      },
+    },
   },
 
 // <if expr="chromeos">
   /** @private */
   onManageAccessibilityFeaturesTap_: function() {
     settings.navigateTo(settings.Route.MANAGE_ACCESSIBILITY);
   },
 // </if>
 
   /** @private */
   onMoreFeaturesTap_: function() {
     window.open(
         'https://chrome.google.com/webstore/category/collection/accessibility');
   },
 });