Use an enum for ChromeVox queue mode.

chrome/browser/resources/chromeos/chromevox/common/nav_description.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 simple container object for the description of a
  * navigation from one object to another.
  *
  */
 
 
 goog.provide('cvox.NavDescription');
 
 goog.require('cvox.AbstractTts');
 goog.require('cvox.ChromeVox');
 goog.require('cvox.CursorSelection');
+goog.require('cvox.QueueMode');
 
 /**
  * A class representing the description of navigation from one object to
  * another.
  * @param {{context: (undefined|string),
  *          text: (string),
  *          userValue: (undefined|string),
  *          annotation: (undefined|string),
  *          earcons: (undefined|Array.<number>),
  *          personality: (undefined|Object),
@@ skipping 56 matching lines @@
  * @param {number} earconId An earcon id to be pushed on to the list of earcon
  * ids to play along with the spoken description of this object.
  */
 cvox.NavDescription.prototype.pushEarcon = function(earconId) {
   this.earcons.push(earconId);
 };
 
 
 /**
  * Speak this nav description with the given queue mode.
- * @param {number=} queueMode The queue mode: cvox.AbstractTts.QUEUE_MODE_FLUSH
- *     for flush, cvox.AbstractTts.QUEUE_MODE_QUEUE for adding to queue.
- * @param {function()=} startCallback Function called when this starts speaking.
- * @param {function()=} endCallback Function called when this ends speaking.
+ * @param {cvox.QueueMode=} queueMode The queue mode.
+ * @param {function()=} opt_startCallback Function called when this
+ *     starts speaking.
+ * @param {function()=} opt_endCallback Function called when this ends speaking.
  */
 cvox.NavDescription.prototype.speak = function(
-    queueMode, startCallback, endCallback) {
+    queueMode, opt_startCallback, opt_endCallback) {
   /**
    * Return a deep copy of PERSONALITY_ANNOTATION for modifying.
    * @return {Object} The newly created properties object.
    */
   function makeAnnotationProps() {
     var properties = {};
     var src = cvox.AbstractTts.PERSONALITY_ANNOTATION;
     for (var key in src) {
       properties[key] = src[key];
     }
     return properties;
   }
 
   var speakArgs = new Array();
   if (this.context) {
     speakArgs.push([this.context, queueMode, makeAnnotationProps()]);
-    queueMode = 1;
+    queueMode = cvox.QueueMode.QUEUE;
   }
 
   speakArgs.push([this.text,
                   queueMode,
                   this.personality ? this.personality : {}]);
-  queueMode = 1;
+  queueMode = cvox.QueueMode.QUEUE;
 
   if (this.userValue) {
     speakArgs.push([this.userValue, queueMode, {}]);
   }
 
   if (this.annotation) {
     speakArgs.push([this.annotation, queueMode, makeAnnotationProps()]);
   }
 
   if (this.hint) {
     speakArgs.push([this.hint, queueMode, makeAnnotationProps()]);
   }
 
   var length = speakArgs.length;
   for (var i = 0; i < length; i++) {
-    if (i == 0 && startCallback) {
-      speakArgs[i][2]['startCallback'] = startCallback;
+    if (i == 0 && opt_startCallback) {
+      speakArgs[i][2]['startCallback'] = opt_startCallback;
     }
-    if (i == length - 1 && endCallback) {
-      speakArgs[i][2]['endCallback'] = endCallback;
+    if (i == length - 1 && opt_endCallback) {
+      speakArgs[i][2]['endCallback'] = opt_endCallback;
     }
     if (this.category) {
       speakArgs[i][2]['category'] = this.category;
     }
     cvox.ChromeVox.tts.speak.apply(cvox.ChromeVox.tts, speakArgs[i]);
   }
 };
 
 
 /**
  * Compares two NavDescriptions.
  * @param {cvox.NavDescription} that A NavDescription.
  * @return {boolean} True if equal.
  */
 cvox.NavDescription.prototype.equals = function(that) {
   return this.context == that.context &&
       this.text == that.text &&
       this.userValue == that.userValue &&
       this.annotation == that.annotation;
 };