Use an enum for ChromeVox queue mode.

chrome/browser/resources/chromeos/chromevox/testing/tester.js

Index: chrome/browser/resources/chromeos/chromevox/testing/tester.js
diff --git a/chrome/browser/resources/chromeos/chromevox/testing/tester.js b/chrome/browser/resources/chromeos/chromevox/testing/tester.js
index ed5f67d3ab620ef7697db438a5c53ec4622507c1..1f226bdac79f08929cffe9937766ba4839a8b57b 100644
--- a/chrome/browser/resources/chromeos/chromevox/testing/tester.js
+++ b/chrome/browser/resources/chromeos/chromevox/testing/tester.js
@@ -11,6 +11,7 @@ goog.require('cvox.ChromeVoxUserCommands');
 goog.require('cvox.LiveRegions');
 goog.require('cvox.NavigationManager');
 goog.require('cvox.NavigationShifter');
+goog.require('cvox.QueueMode');
 goog.require('cvox.TestHost');
 goog.require('cvox.TestMathJax');
 goog.require('cvox.TestMsgs');
@@ -48,7 +49,7 @@ cvox.ChromeVoxTester.setUp = function(doc) {
 
   // Init LiveRegions with a date of 0 so that the initial delay before
   // things is spoken is skipped.
-  cvox.LiveRegions.init(new Date(0), cvox.AbstractTts.QUEUE_MODE_QUEUE, false);
+  cvox.LiveRegions.init(new Date(0), cvox.QueueMode.QUEUE, false);
 
   cvox.ChromeVoxEventWatcher.init(doc);
   window.console.log('done setup');
@@ -115,7 +116,7 @@ cvox.ChromeVoxTester.setStrategy = function(strategy) {
  */
 cvox.ChromeVoxTester.readFromHere = function() {
   cvox.ChromeVox.navigationManager.startReading(
-         cvox.AbstractTts.QUEUE_MODE_FLUSH);
+         cvox.QueueMode.FLUSH);
 };
 
 /**