Make earcon ids strings instead of numbers.

chrome/browser/resources/chromeos/chromevox/host/chrome/earcons_background.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 Earcons library that uses the HTML5 Audio element to play back
  * auditory cues.
  *
  */
 
@@ skipping 36 matching lines @@
 
 /**
  * @override
  */
 cvox.EarconsBackground.prototype.playEarcon = function(earcon) {
   goog.base(this, 'playEarcon', earcon);
   if (!this.enabled) {
     return;
   }
   if (window['console']) {
-    window['console']['log']('Earcon ' + this.getEarconName(earcon));
+    window['console']['log']('Earcon ' + earcon);
   }
 
   this.currentAudio = this.audioMap[earcon];
   if (!this.currentAudio) {
     this.currentAudio = new Audio(chrome.extension.getURL(this.getBaseUrl() +
-        this.getEarconFilename(earcon)));
+        earcon + '.ogg'));
     this.audioMap[earcon] = this.currentAudio;
   }
   try {
     this.currentAudio.currentTime = 0;
   } catch (e) {
   }
   if (this.currentAudio.paused) {
     this.currentAudio.volume = 0.7;
     this.currentAudio.play();
   }
 };
 
 
 /**
  * The base URL for  loading eracons.
  * @type {string}
  */
 cvox.EarconsBackground.BASE_URL = 'chromevox/background/earcons/';