Added basic browser test for window.print() from Chrome apps.

chrome/browser/resources/print_preview/print_preview.js

 // Copyright (c) 2012 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.
 
 // TODO(rltoscano): Move data/* into print_preview.data namespace
 
 var localStrings = new LocalStrings(templateData);
 
 <include src="component.js"/>
 
@@ skipping 243 matching lines @@
           print_preview.NativeLayer.EventType.FILE_SELECTION_COMPLETE,
           this.onFileSelectionComplete_.bind(this));
       this.tracker.add(
           this.nativeLayer_,
           print_preview.NativeLayer.EventType.SETTINGS_INVALID,
           this.onSettingsInvalid_.bind(this));
       this.tracker.add(
           this.nativeLayer_,
           print_preview.NativeLayer.EventType.DISABLE_SCALING,
           this.onDisableScaling_.bind(this));
+      this.tracker.add(
+          this.nativeLayer_,
+          print_preview.NativeLayer.EventType.AUTO_CANCEL_FOR_TESTING,
+          this.close_.bind(this));
 
       this.tracker.add(
           $('system-dialog-link'),
           'click',
           this.openSystemPrintDialog_.bind(this));
       this.tracker.add(
           $('cloud-print-dialog-link'),
           'click',
           this.onCloudPrintDialogLinkClick_.bind(this));
       this.tracker.add(
@@ skipping 671 matching lines @@
 <include src="search/recent_destination_list.js"/>
 <include src="search/destination_list_item.js"/>
 <include src="search/destination_search.js"/>
 <include src="search/search_box.js"/>
 <include src="search/fedex_tos.js"/>
 
 window.addEventListener('DOMContentLoaded', function() {
   printPreview = new print_preview.PrintPreview();
   printPreview.initialize();
 });