[MD settings] specify @override on created, ready, and attached

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 76 matching lines @@
       type: Boolean,
       value: false,
     },
   },
 
   observers: [
     'maybeGetTimeZoneList_(' +
         'prefs.cros.system.timezone.value, timeZoneAutoDetect_)',
   ],
 
+  /** @override */
   attached: function() {
     this.addWebUIListener(
         'time-zone-auto-detect-policy',
         this.onTimeZoneAutoDetectPolicyChanged_.bind(this));
     this.addWebUIListener(
         'can-set-date-time-changed', this.onCanSetDateTimeChanged_.bind(this));
 
     chrome.send('dateTimePageReady');
     this.maybeGetTimeZoneList_();
   },
@@ skipping 90 matching lines @@
    */
   setTimeZoneList_: function(timeZones) {
     this.timeZoneList_ = timeZones.map(function(timeZonePair) {
       return {
         name: timeZonePair[1],
         value: timeZonePair[0],
       };
     });
   },
 });