Added to options page to let users change keyboard mappings.

chrome/browser/resources/chromeos/switch_access/auto_scan_manager.js

 // Copyright 2017 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.
 
 /**
  * Class to handle changes to auto-scan.
  *
  * @constructor
  * @param {SwitchAccessInterface} switchAccess
  */
 function AutoScanManager(switchAccess) {
   /**
    * SwitchAccess reference.
+   *
    * @private {SwitchAccessInterface}
    */
   this.switchAccess_ = switchAccess;
 
   /**
    * Auto-scan interval ID.
    *
    * @private {number|undefined}
    */
   this.intervalID_;
 
   /**
    * Length of auto-scan interval in milliseconds.
    *
    * @private {number}
    */
-  this.scanTime_ = switchAccess.switchAccessPrefs.getNumberPref('autoScanTime');
+  this.scanTime_ = switchAccess.getNumberPref('autoScanTime');
 
-  let enabled = switchAccess.switchAccessPrefs.getBooleanPref('enableAutoScan');
+  let enabled = switchAccess.getBooleanPref('enableAutoScan');
   if (enabled)
     this.start_();
 }
 
 AutoScanManager.prototype = {
   /**
    * Stop the window from moving to the next node at a fixed interval.
    *
    * @private
    */
@@ skipping 50 matching lines @@
    * Update this.scanTime_ to |scanTime|. Then, if auto-scan is currently
    * running, restart it.
    *
    * @param {number} scanTime Auto-scan interval time in milliseconds.
    */
   setScanTime: function(scanTime) {
     this.scanTime_ = scanTime;
     this.restartIfRunning();
   },
 };