[Gallery app] Make the background page use BackgroundBase class

ui/file_manager/gallery/js/gallery_scripts.js

 // Copyright 2014 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.
 
 // The include directives are put into Javascript-style comments to prevent
 // parsing errors in non-flattened mode. The flattener still sees them.
 // Note that this makes the flattener to comment out the first line of the
 // included file but that's all right since any javascript file should start
 // with a copyright comment anyway.
 
 //<include src="../../file_manager/foreground/js/metrics_base.js">
 //<include src="../../file_manager/foreground/js/metrics.js">
 
 //<include src="../../file_manager/common/js/lru_cache.js">
 //<include src="../../image_loader/image_loader_client.js">
 
 //<include src="../../../webui/resources/js/cr.js">
 //<include src="../../../webui/resources/js/util.js">
 //<include src="../../../webui/resources/js/event_tracker.js">
 //<include src="../../../webui/resources/js/load_time_data.js">
+//<include src="../../../webui/resources/js/i18n_template_no_process.js">
 
 //<include src="../../../webui/resources/js/cr/ui.js">
 //<include src="../../../webui/resources/js/cr/event_target.js">
 //<include src="../../../webui/resources/js/cr/ui/touch_handler.js">
 //<include src="../../../webui/resources/js/cr/ui/array_data_model.js">
 //<include src="../../../webui/resources/js/cr/ui/dialogs.js">
 //<include src="../../../webui/resources/js/cr/ui/list_item.js">
 //<include src="../../../webui/resources/js/cr/ui/list_selection_model.js">
 //<include
 //    src="../../../webui/resources/js/cr/ui/list_single_selection_model.js">
@@ skipping 40 matching lines @@
 //<include src="ribbon.js">
 //<include src="slide_mode.js">
 
 // Exports
 window.ImageUtil = ImageUtil;
 window.ImageUtil.metrics = metrics;
 window.Gallery = Gallery;
 window.util = util;
 
 })();