Adds option to enable CSS backgrounds for printing.

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 877 matching lines @@
 <include src="data/ticket_items/custom_margins.js"/>
 <include src="data/ticket_items/collate.js"/>
 <include src="data/ticket_items/color.js"/>
 <include src="data/ticket_items/copies.js"/>
 <include src="data/ticket_items/duplex.js"/>
 <include src="data/ticket_items/header_footer.js"/>
 <include src="data/ticket_items/landscape.js"/>
 <include src="data/ticket_items/margins_type.js"/>
 <include src="data/ticket_items/page_range.js"/>
 <include src="data/ticket_items/fit_to_page.js"/>
+<include src="data/ticket_items/css_background.js"/>
 
 <include src="native_layer.js"/>
 <include src="print_preview_animations.js"/>
 <include src="cloud_print_interface.js"/>
 <include src="print_preview_utils.js"/>
 <include src="print_header.js"/>
 <include src="metrics.js"/>
 
 <include src="settings/page_settings.js"/>
 <include src="settings/copies_settings.js"/>
@@ skipping 13 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();
 });