Compile print_preview, part 3: reduce down to 185 errors

chrome/browser/resources/print_preview/component.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.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * Class that represents a UI component.
    * @constructor
@@ skipping 138 matching lines @@
         this.removeChild(this.children_[0]);
       }
     },
 
     /**
      * @param {string} query Selector query to select an element starting from
      *     the component's root element using a depth first search for the first
      *     element that matches the query.
      * @return {!HTMLElement} Element selected by the given query.
      * TODO(alekseys): Check all call sites and rename this function to
      *     something like getRequiredChildElement.

[Dan Beam, 2014/09/29 18:42:00]

either remove this ^ or figure out how to address querySelector() returning null

[Vitaly Pavlenko, 2014/10/01 00:33:37]

Removed the assert for now.

      */
     getChildElement: function(query) {
-      return assert(this.element_.querySelector(query));
+      return assertInstanceof(this.element_.querySelector(query), HTMLElement);
     },
 
     /**
      * Sets the component's element.
      * @param {Element} element HTML element to set as the component's element.
      * @protected
      */
     setElementInternal: function(element) {
       this.element_ = element;
     },
 
     /**
      * Decorates the given element for use as the element of the component.
      * @protected
      */
     decorateInternal: function() { /*abstract*/ },
 
     /**
      * Clones a template HTML DOM tree.
      * @param {string} templateId Template element ID.
      * @param {boolean=} opt_keepHidden Whether to leave the cloned template
      *     hidden after cloning.
      * @return {Element} Cloned element with its 'id' attribute stripped.
      * @protected
      */
     cloneTemplateInternal: function(templateId, opt_keepHidden) {
       var templateEl = $(templateId);
       assert(templateEl != null,
              'Could not find element with ID: ' + templateId);
-      var el = templateEl.cloneNode(true);
+      var el = assertInstanceof(templateEl.cloneNode(true), HTMLElement);
       el.id = '';
       if (!opt_keepHidden) {
         setIsVisible(el, true);
       }
       return el;
     }
   };
 
   return {
     Component: Component
   };
 });