Trigger a tab updated event if the favicon URL changes.

chrome/test/data/extensions/api_test/tabs/on_updated/test.js

 // Copyright (c) 2011 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.
 
 var expectedEventData;
 var capturedEventData;
 var shouldIgnore;
 
 function expect(data, ignoreFunc) {
   expectedEventData = data;
   capturedEventData = [];
   shouldIgnore = ignoreFunc;
 }
 
 function checkExpectations() {
   if (capturedEventData.length < expectedEventData.length) {
     return;
   }
   chrome.test.assertEq(JSON.stringify(expectedEventData),
       JSON.stringify(capturedEventData));
   chrome.test.succeed();
 }
 
 var getURL = chrome.extension.getURL;
 
 chrome.tabs.onUpdated.addListener(function(tabId, info, tab) {
-  console.log('---onUpdated: ' + info.status + ', ' + info.url);
+  console.log('---onUpdated: ' + info.status + ', ' + info.url + '. ' +
+               info.favIconUrl);
   if (shouldIgnore && shouldIgnore(info)) {
     return;
   }
   capturedEventData.push(info);
   checkExpectations();
 });
 
 chrome.test.runTests([
   function browserThenRendererInitiated() {
     // Note that a.html will set it's location.href to b.html, creating a
@@ skipping 63 matching lines @@
 
   function internalAnchorNavigated() {
     expect([
       { status: 'loading', url: getURL('internalAnchorNavigated/a.html') },
       { status: 'complete' },
       { status: 'loading', url: getURL('internalAnchorNavigated/a.html#b') },
       { status: 'complete' },
     ]);
 
     chrome.tabs.create({ url: getURL('internalAnchorNavigated/a.html') });
+  },
+
+  function faviconLoaded() {
+    expect([
+      { status: 'loading', url: getURL('favicon/a.html') },
+      { status: 'complete' },
+      { favIconUrl: getURL('favicon/favicon.png') },
+    ]);
+
+    chrome.tabs.create({ url: getURL('favicon/a.html') });
   }
 ]);