Add Physical Web WebUI Default Url Icon

components/physical_web/webui/resources/physical_web.js

 // Copyright (c) 2016 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.
 
 /**
  * Takes the |nearbyUrlsData| input argument which holds metadata for web pages
  * broadcast by nearby devices.
  * @param {Object} nearbyUrlsData Information about web pages broadcast by
  *      nearby devices
  */
@@ skipping 12 matching lines @@
 
 function returnNearbyURLs(nearbyUrlsData) {
   var bodyContainer = $('body-container');
   renderTemplate(nearbyUrlsData);
   bodyContainer.hidden = false;
 
   if (nearbyUrlsData['metadata'].length == 0) {
     var emptyMessage = $('empty-list-container');
     emptyMessage.hidden = false;
   }
+  assignImageLoadErrorHandlers();
+}
+
+function assignImageLoadErrorHandlers() {
+  var pwIcons = document.querySelectorAll('.physicalWebIcon');
+  pwIcons.forEach(function(e) {
+    let img = e.getElementsByTagName('img')[0];

[mmocny, 2017/03/23 20:58:39]

Could we just change the querySelectorAll to do this for us?  You can use nested
selectors, try this:

'.physicalWebIcon > img'

[Ran, 2017/03/24 17:48:29]

Done.

+    img.addEventListener('error', function() {
+      img.src =
+          'chrome://physical-web/ic_link_grey600_36dp.png';
+    });
+  });
 }
 
 document.addEventListener('DOMContentLoaded', requestNearbyURLs);