ChromeOS: removed outdated --disable-timezone-tracking-option switch.

chrome/browser/resources/settings/date_time_page/date_time_page.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
  * 'settings-date-time-page' is the settings page containing date and time
  * settings.
  */
 
@@ skipping 56 matching lines @@
      */
     systemTimeZoneDetectionPolicyValue_: {
       type: Number,
       value: function() {
         return loadTimeData.valueExists('systemTimeZoneDetectionPolicyValue') ?
             /** @type {settings.AutomaticTimezoneDetectionPolicy} */(
                 loadTimeData.getInteger('systemTimeZoneDetectionPolicyValue')) :
             null;
       },
     },
-
-    /**
-     * Hides the time zone auto-detection feature when the
-     * --disable-timezone-tracking-option flag is set.
-     * @private
-     */
-    hideTimeZoneDetection_: {
-      type: Boolean,
-      value: function() {
-        return loadTimeData.valueExists('hideTimeZoneDetection') &&
-               loadTimeData.getBoolean('hideTimeZoneDetection');
-      },
-      readOnly: true,
-    },
   },
 
   observers: [
     // TODO(michaelpg): Implement a BrowserProxy to listen for policy changes.
     'updateTimeZoneDetectionCheckbox_(' +
         'prefs.settings.resolve_timezone_by_geolocation.value,' +
         'systemTimeZoneManaged_,' +
         'systemTimeZoneDetectionManaged_,' +
         'systemTimeZoneDetectionPolicyValue_)',
   ],
 
   /**
    * Processes all the time zone preferences and policy interactions in one
    * observer function instead of complicating the HTML with computed bindings.
    * @param {boolean} userPrefValue
    * @param {boolean} systemTimeZoneManaged
    * @param {boolean} systemTimeZoneDetectionManaged
    * @param {?settings.AutomaticTimezoneDetectionPolicy}
    *     systemTimeZoneDetectionPolicyValue
    */
   updateTimeZoneDetectionCheckbox_(userPrefValue,
                                    systemTimeZoneManaged,
                                    systemTimeZoneDetectionManaged,
                                    systemTimeZoneDetectionPolicyValue) {
-    // Do nothing if the feature is disabled by a flag.
-    if (this.hideTimeZoneDetection_)
-      return;
-
     var checkbox = this.$.timeZoneDetectionCheckbox;
 
     // Time zone auto-detection is disabled when the time zone is managed.
     if (systemTimeZoneManaged) {
       checkbox.disabled = true;
       checkbox.checked = false;
       return;
     }
 
     // The time zone auto-detection policy may force-disable auto-detection.
@@ skipping 11 matching lines @@
     checkbox.disabled = false;
     checkbox.checked = userPrefValue;
   },
 
   /** @param {!Event} e */
   onTimeZoneDetectionCheckboxChange_: function(e) {
     this.setPrefValue(
         'settings.resolve_timezone_by_geolocation', e.target.checked);
   },
 });