Use an enum for ChromeVox queue mode.

chrome/browser/resources/chromeos/chromevox/host/testing/tts.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 Dummy implementation of TTS for testing.
  *
  */
 
 goog.provide('cvox.TestTts');
@@ skipping 113 matching lines @@
 cvox.TestTts.prototype.getUtteranceList = function() {
   var result = [];
   for (var i = 0; i < this.utterances_.length; i++) {
     result.push(this.utterances_[i].text);
   }
   return result;
 };
 
 /**
  * Return a list of strings of what was spoken by tts.speak().
- * @return {Array.<{text: string, queueMode: number}>}
+ * @return {Array.<{text: string, queueMode: cvox.QueueMode}>}
  *     A list of info about all utterances spoken since
  *     initialization or the last call to clearUtterances.
  */
 cvox.TestTts.prototype.getUtteranceInfoList = function() {
   return this.utterances_;
 };
 
 /** @override */
 cvox.HostFactory.ttsConstructor = cvox.TestTts;