Compile print_preview, part 6: reduce down to 48 errors

chrome/browser/resources/print_preview/settings/media_size_settings.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.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * Encapsulates all settings and logic related to the media size selection UI.
    * @param {!print_preview.ticket_items.MediaSize} ticketItem Used to read and
@@ skipping 22 matching lines @@
     },
 
     /** @override */
     set isEnabled(isEnabled) {
       this.select_.disabled = !isEnabled;
     },
 
     /** @override */
     enterDocument: function() {
       print_preview.SettingsSection.prototype.enterDocument.call(this);
-      this.tracker.add(this.select_, 'change', this.onSelectChange_.bind(this));
+      this.tracker.add(assert(this.select_),
+                       'change',
+                       this.onSelectChange_.bind(this));
       this.tracker.add(
           this.ticketItem_,
           print_preview.ticket_items.TicketItem.EventType.CHANGE,
           this.onTicketItemChange_.bind(this));
     },
 
     /**
      * @return {HTMLSelectElement} Select element containing media size options.
      * @private
      */
@@ skipping 85 matching lines @@
       this.updateSelect_();
       this.updateUiStateInternal();
     }
   };
 
   // Export
   return {
     MediaSizeSettings: MediaSizeSettings
   };
 });