Add policy to use system default printer

chrome/test/data/webui/print_preview/print_preview_ui_browsertest.js

 // Copyright 2017 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 Runs the Print Preview tests. */
 
 var ROOT_PATH = '../../../../../';
 
 /**
  * @constructor
@@ skipping 96 matching lines @@
 // Disable accessibility errors for some tests.
 [
   'AdvancedSettings1Option',
   'AdvancedSettings2Options',
 ].forEach(function(testName) {
   TEST_F('PrintPreviewUIBrowserTest', testName, function() {
     this.accessibilityIssuesAreErrors = false;
     mocha.grep(new RegExp(testName + '\\b')).run();
   });
 });
+
+GEN('#if !defined(OS_CHROMEOS)');
+TEST_F('PrintPreviewUIBrowserTest', 'SystemDefaultPrinterPolicy', function() {
+  loadTimeData.overrideValues({useSystemDefaultPrinter: true});
+  mocha.grep(new RegExp('SystemDefaultPrinterPolicy' + '\\b')).run();
+});
+GEN('#endif');