MD Settings: Restore focus when exiting various subpages, part 2.

chrome/browser/resources/settings/android_apps_page/android_apps_page.js

 // Copyright 2016 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
  * 'android-apps-page' is the settings page for enabling android apps.
  */
 
 Polymer({
   is: 'settings-android-apps-page',
 
   behaviors: [I18nBehavior, PrefsBehavior],
 
   properties: {
     /** Preferences state. */
     prefs: {
       type: Object,
       notify: true,
     },
 
     /** @private {!AndroidAppsInfo|undefined} */
     androidAppsInfo_: Object,
+
+    /** @private {!Map<string, string>} */
+    focusConfig_: {
+      type: Object,
+      value: function() {
+        var map = new Map();
+        map.set(
+            settings.Route.ANDROID_APPS_DETAILS.path,
+            '#android-apps .subpage-arrow');
+        return map;
+      },
+    },
   },
 
   /** @private {?settings.AndroidAppsBrowserProxy} */
   browserProxy_: null,
 
   /** @override */
   created: function() {
     this.browserProxy_ = settings.AndroidAppsBrowserProxyImpl.getInstance();
   },
 
@@ skipping 19 matching lines @@
     this.setPrefValue('arc.enabled', true);
     event.stopPropagation();
   },
 
   /** @private */
   onSubpageTap_: function() {
     if (this.androidAppsInfo_.appReady)
       settings.navigateTo(settings.Route.ANDROID_APPS_DETAILS);
   },
 });