Make earcon ids strings instead of numbers.

chrome/browser/resources/chromeos/chromevox/chromevox/injected/api_implementation.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 Implentation of ChromeVox's public API.
  *
  */
 
 goog.provide('cvox.ApiImplementation');
@@ skipping 181 matching lines @@
   }
 };
 
 /**
  * Plays the specified earcon sound.
  *
  * @param {string} earcon An earcon name.
  */
 cvox.ApiImplementation.playEarcon = function(earcon) {
   if (cvox.ChromeVox.isActive) {
-    cvox.ChromeVox.earcons.playEarconByName(earcon);
+    cvox.ChromeVox.earcons.playEarcon(cvox.Earcon[earcon]);

[Peter Lundblad, 2015/08/27 19:54:56]

Should guard against passing in undefined to this function if the api client
passes in an invalid value.

[dmazzoni, 2015/08/27 21:27:47]

Done.

   }
 };
 
 /**
  * Synchronizes ChromeVox's internal cursor to a node by id.
  *
  * @param {Object} nodeRef A serializable reference to a node.
  * @param {boolean=} speakNode If true, speaks out the node.
  */
 cvox.ApiImplementation.syncToNodeRef = function(nodeRef, speakNode) {
@@ skipping 187 matching lines @@
  * @param {...string} constraints Additional constraints.
  */
 cvox.ApiImplementation.Math.defineRule =
     function(name, dynamic, action, prec, constraints) {
   var mathStore = cvox.MathmlStore.getInstance();
   var constraintList = Array.prototype.slice.call(arguments, 4);
   var args = [name, dynamic, action, prec].concat(constraintList);
 
   mathStore.defineRule.apply(mathStore, args);
 };