Do more strict checking when calling into MathJaX

chrome/browser/resources/chromeos/chromevox/cvox2/injected/loader.js

 // Copyright 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.
 
 goog.require('cvox.ApiImplementation');
 goog.require('KeyboardHandler');
 
 /**
  * Initializes minimal content script.
  */
 function initMin() {
   if (cvox.ChromeVox.isChromeOS) {
-    cvox.ApiImplementation.init();
+    cvox.ApiImplementation.init(true);
     return;
   }
 
   if (cvox.ChromeVox.isClassicEnabled_ === undefined) {
     window.setTimeout(function() {
       initMin();
     }, 500);
     return;
   }
 
   if (cvox.ChromeVox.isClassicEnabled_)
     return;
 
   new KeyboardHandler();
 }
 
 initMin();