Support basic stereo pan positioning for earcons

chrome/browser/resources/chromeos/chromevox/cvox2/background/next_earcons.js

 // Copyright 2015 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 EarconEngine to play back
  * auditory cues.
  */
 
 
@@ skipping 25 matching lines @@
   /**
    * @return {string} The human-readable name of the earcon set.
    */
   getName: function() {
     return 'ChromeVox Next earcons';
   },
 
   /**
    * @override
    */
-  playEarcon: function(earcon) {
+  playEarcon: function(earcon, opt_location) {
     if (!cvox.AbstractEarcons.enabled) {
       return;
     }
     console.log('Earcon ' + earcon);
-
+    if (ChromeVoxState.instance.currentRange &&
+        ChromeVoxState.instance.currentRange.isValid()) {
+      var node = ChromeVoxState.instance.currentRange.start.node;
+      var rect = opt_location || node.location;
+      var container = node.root.location;
+      this.engine_.setPositionForRect(rect, container);
+    }
     switch (earcon) {
       case cvox.Earcon.ALERT_MODAL:
       case cvox.Earcon.ALERT_NONMODAL:
         this.engine_.onAlert();
         break;
       case cvox.Earcon.BUTTON:
         this.engine_.onButton();
         break;
       case cvox.Earcon.CHECK_OFF:
         this.engine_.onCheckOff();
@@ skipping 59 matching lines @@
    * @override
    */
   cancelEarcon: function(earcon) {
     switch (earcon) {
       case cvox.Earcon.PAGE_START_LOADING:
         this.engine_.cancelProgress();
         break;
     }
   },
 };