Fix math support on wikipedia.

chrome/browser/resources/chromeos/chromevox/common/dom_util.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.
 
 /**
  * @fileoverview A collection of JavaScript utilities used to simplify working
  * with the DOM.
  */
 
 
@@ skipping 2429 matching lines @@
  * @param {Node} node The node to be tested.
  * @return {boolean} Whether or not a node has an image with class TeX or LaTeX.
  */
 cvox.DomUtil.isMathImg = function(node) {
   if (!node || !node.tagName || !node.className) {
     return false;
   }
   if (node.tagName != 'IMG') {
     return false;
   }
-  var className = node.className.toLowerCase();
-  return cvox.DomUtil.ALT_MATH_CLASSES.tex.indexOf(className) != -1 ||
-      cvox.DomUtil.ALT_MATH_CLASSES.asciimath.indexOf(className) != -1;
+  for (var i = 0, className; className = node.classList.item(i); i++) {
+    className = className.toLowerCase();
+    if (cvox.DomUtil.ALT_MATH_CLASSES.tex.indexOf(className) != -1 ||
+        cvox.DomUtil.ALT_MATH_CLASSES.asciimath.indexOf(className) != -1) {
+      return true;
+    }
+  }
+  return false;
 };
 
 
 /**
  * Checks to see whether a node is a MathML node.
  * !! This is necessary as Chrome currently does not upperCase Math tags !!
  * @param {Node} node The node to be tested.
  * @return {boolean} Whether or not a node is a MathML node.
  */
 cvox.DomUtil.isMathml = function(node) {
@@ skipping 129 matching lines @@
         var describedNode = document.getElementById(describedById);
         if (describedNode) {
           desc += ' ' + cvox.DomUtil.getName(
               describedNode, true, true, true);
         }
       }
     }
   }
   return desc;
 };