Use window.URL instead of window.webkitURL.

chrome/common/extensions/docs/templates/articles/app_codelab8_webresources.html

 <h1 id="lab_8_web_resources">Access Web Resources</h1>
 
 <p>Chrome Apps have a strict
 <a href="contentSecurityPolicy.html">Content Security Policy</a>
 which will not let the user execute code or load resources that are hosted remotely.</p>
 
 <p>Many applications, however, need to be able to load and display content from a remote location. A News Reader, for example, needs to display remote content inline or load and show images from a remote URL.</p>
 
 <h2 id="loading_external_web_content_into_an_element">Load external web content</h2>
 
@@ skipping 205 matching lines @@
 that will start a XHR request and execute a callback with a Blob URL.
 <a href="https://github.com/GoogleChrome/chrome-app-codelab/blob/master/lab8_webresources/angularjs/2_loading_resources/loader.js">AngularJS loader.js</a> and
 <a href="https://github.com/GoogleChrome/chrome-app-codelab/blob/master/lab8_webresources/javascript/2_loading_resources/loader.js">JavaScript loader.js</a> are the same:
 </p>
 
 <pre data-filename="loader.js">
 var loadImage = function(uri, callback) {
   var xhr = new XMLHttpRequest();
   xhr.responseType = &#39;blob&#39;;
   xhr.onload = function() {
-    callback(window.webkitURL.createObjectURL(xhr.response), uri);
+    callback(window.URL.createObjectURL(xhr.response), uri);
   }
   xhr.open(&#39;GET&#39;, uri, true);
   xhr.send();
 }
 </pre>
 
 <p>In the
 <a href="https://github.com/GoogleChrome/chrome-app-codelab/blob/master/lab8_webresources/angularjs/2_loading_resources/controller.js">AngularJS controller.js</a> or
 <a href="">JavaScript controller.js</a>,
 add a new method that will search the Todo list looking for images that are not loaded yet:
@@ skipping 219 matching lines @@
 
 <ul>
 <li><a href="webview_tag.html">Webview Tag API</a> reference</li>
 <li><a href="app_external.html">Embed Content</a> tutorial</li>
 </ul>
 
 <h2 id="what_39_s_next_">What's next?</h2>
 
 <p>In <a href="app_codelab_10_publishing.html">8 - Publish App</a>,
 we finish off with instructions on how to publish your app in the Chrome Web Store.</p>