MD Settings: CrOS: Focus elements on dialog close

chrome/browser/resources/settings/printing_page/cups_printers.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-cups-printers' is a component for showing CUPS
  * Printer settings subpage (chrome://md-settings/cupsPrinters). It is used to
  * set up legacy & non-CloudPrint printers on ChromeOS by leveraging CUPS (the
  * unix printing system) and the many open source drivers built for CUPS.
  */
@@ skipping 100 matching lines @@
    */
   printersChanged_: function(cupsPrintersList) {
     this.printers = cupsPrintersList.printerList;
   },
 
   /** @private */
   onAddPrinterTap_: function() {
     this.$.addPrinterDialog.open();
     this.$.addPrinterErrorMessage.hidden = true;
   },
+
+  /** @private */
+  onAddPrinterDialogClose_: function() {
+    this.$$('#addPrinter').focus();
+  },
 });