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

chrome/browser/resources/settings/about_page/about_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 'settings-about-page' contains version and OS related
  * information.
  */
 Polymer({
   is: 'settings-about-page',
@@ skipping 55 matching lines @@
       type: Boolean,
       computed: 'computeShowRelaunchAndPowerwash_(' +
           'currentUpdateStatusEvent_, targetChannel_)',
     },
 
     /** @private */
     showCheckUpdates_: {
       type: Boolean,
       computed: 'computeShowCheckUpdates_(currentUpdateStatusEvent_)',
     },
+
+    /** @private {!Map<string, string>} */
+    focusConfig_: {
+      type: Object,
+      value: function() {
+        var map = new Map();
+        map.set(
+            settings.Route.DETAILED_BUILD_INFO.path,
+            '#detailed-build-info-trigger');
+        return map;
+      },
+    }
 // </if>
   },
 
   observers: [
 // <if expr="not chromeos">
     'updateShowUpdateStatus_(' +
         'obsoleteSystemInfo_, currentUpdateStatusEvent_)',
     'updateShowRelaunch_(currentUpdateStatusEvent_)',
     'updateShowButtonContainer_(showRelaunch_)',
 // </if>
@@ skipping 323 matching lines @@
     });
   },
 
 // <if expr="_google_chrome">
   /** @private */
   onReportIssueTap_: function() {
     this.aboutBrowserProxy_.openFeedbackDialog();
   },
 // </if>
 });