Use an enum for ChromeVox queue mode.

chrome/browser/resources/chromeos/chromevox/chromevox/messages/spoken_messages.js

Index: chrome/browser/resources/chromeos/chromevox/chromevox/messages/spoken_messages.js
diff --git a/chrome/browser/resources/chromeos/chromevox/chromevox/messages/spoken_messages.js b/chrome/browser/resources/chromeos/chromevox/chromevox/messages/spoken_messages.js
index 49e2575793d649b47547e4500bc44e9056dacd26..ba2c55fb7b59d50187794ac93254ac80425a8cc7 100644
--- a/chrome/browser/resources/chromeos/chromevox/chromevox/messages/spoken_messages.js
+++ b/chrome/browser/resources/chromeos/chromevox/chromevox/messages/spoken_messages.js
@@ -30,19 +30,19 @@ cvox.SpokenMessages.messages = [];
  * Speaks the message chain and interrupts any on-going speech.
  */
 cvox.SpokenMessages.speakFlush = function() {
-  cvox.SpokenMessages.speak(cvox.AbstractTts.QUEUE_MODE_FLUSH);
+  cvox.SpokenMessages.speak(cvox.QueueMode.FLUSH);
 };
 
 /**
  * Speaks the message chain after on-going speech finishes.
  */
 cvox.SpokenMessages.speakQueued = function() {
-  cvox.SpokenMessages.speak(cvox.AbstractTts.QUEUE_MODE_QUEUE);
+  cvox.SpokenMessages.speak(cvox.QueueMode.QUEUE);
 };
 
 /**
  * Speak the message chain.
- * @param {number} mode The speech queue mode.
+ * @param {cvox.QueueMode} mode The speech queue mode.
  */
 cvox.SpokenMessages.speak = function(mode) {
   for (var i = 0; i < cvox.SpokenMessages.messages.length; ++i) {
@@ -81,16 +81,16 @@ cvox.SpokenMessages.speak = function(mode) {
                              cvox.AbstractTts.PERSONALITY_ANNOUNCEMENT);
 
     // Always queue after the first message.
-    mode = cvox.AbstractTts.QUEUE_MODE_QUEUE;
+    mode = cvox.QueueMode.QUEUE;
   }
 
   cvox.SpokenMessages.messages = [];
-}
+};
 
-  /**
-   * The newest message.
-   * @return {cvox.SpokenMessage} The newest (current) message.
-   */
+/**
+ * The newest message.
+ * @return {cvox.SpokenMessage} The newest (current) message.
+ */
 cvox.SpokenMessages.currentMessage = function() {
   if (cvox.SpokenMessages.messages.length == 0)
     throw 'Invalid usage of SpokenMessages; start the chain using $m()';
@@ -102,13 +102,13 @@ cvox.SpokenMessages.currentMessage = function() {
  * This will modify the way the message gets read.
  * For example, if the count is 2, the message becomes pluralized according
  * to our i18n resources. The message "2 links" is a possible output.
- * @param {Number} count Quantifies current message.
+ * @param {number} count Quantifies current message.
  * @return {Object} This object, useful for chaining.
  */
 cvox.SpokenMessages.withCount = function(count) {
   cvox.SpokenMessages.currentMessage().count = count;
   return cvox.SpokenMessages;
-}
+};
 
 /**
  * Quantifies the current message.
@@ -123,7 +123,7 @@ cvox.SpokenMessages.andIndexTotal = function(index, total) {
   newMessage.raw = cvox.ChromeVox.msgs.getMsg('index_total', [index, total]);
   cvox.SpokenMessages.messages.push(newMessage);
   return cvox.SpokenMessages;
-}
+};
 
 /**
  * Ends a message. with an appropriate marker.
@@ -156,7 +156,7 @@ cvox.SpokenMessages.andRawMessage = function(message) {
   newMessage.raw = message;
   cvox.SpokenMessages.messages.push(newMessage);
   return cvox.SpokenMessages;
-}
+};
 
 /**
  * Pauses after the message, with an appropriate marker.
@@ -166,4 +166,9 @@ cvox.SpokenMessages.andPause = function() {
   return cvox.SpokenMessages.andMessage('pause');
 };
 
+/**
+ * Adds a message.
+ * @param {string|Array} messageId The id of the message.
+ * @return {Object} This object, useful for chaining.
+ */
 cvox.$m = cvox.SpokenMessages.andMessage;