ChromeOS: implement per-user time zone preferences.

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 72 matching lines @@
      * by network time, so default to false to initially hide the button.
      * @private
      */
     canSetDateTime_: {
       type: Boolean,
       value: false,
     },
   },
 
   observers: [
-    'maybeGetTimeZoneList_(' +
+    'maybeGetTimeZoneListPerUser_(' +
+        'prefs.settings.timezone.value, timeZoneAutoDetect_)',
+    'maybeGetTimeZoneListPerSystem_(' +
         '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));
@@ skipping 63 matching lines @@
         return true;
       case settings.TimeZoneAutoDetectPolicy.FORCED_OFF:
         return false;
       default:
         assertNotReached();
     }
   },
 
   /**
    * Fetches the list of time zones if necessary.
+   * @param {boolean=} perUserTimeZoneMode Expected value of per-user time zone.
    * @private
    */
-  maybeGetTimeZoneList_: function() {
+  maybeGetTimeZoneList_: function(perUserTimeZoneMode) {
+    if (typeof(perUserTimeZoneMode) !== 'undefined') {
+      /* This method is called as observer. Skip if if current mode does not
+       * match expected.
+       */
+      if (perUserTimeZoneMode !=
+          this.getPref('cros.flags.per_user_timezone_enabled').value) {
+        return;
+      }
+    }
     // Only fetch the list once.
     if (this.timeZoneList_.length > 1 || !CrSettingsPrefs.isInitialized)
       return;
 
     // If auto-detect is enabled, we only need the current time zone.
-    if (this.timeZoneAutoDetect_ &&
-        this.getPref('cros.system.timezone').value ==
-            this.timeZoneList_[0].value) {
-      return;
+    if (this.timeZoneAutoDetect_) {
+      var isPerUserTimezone =
+          this.getPref('cros.flags.per_user_timezone_enabled').value;
+      if (this.timeZoneList_[0].value ==
+          (isPerUserTimezone ? this.getPref('settings.timezone').value :
+                               this.getPref('cros.system.timezone').value)) {
+        return;
+      }
     }
 
     cr.sendWithPromise('getTimeZones').then(this.setTimeZoneList_.bind(this));
   },
 
   /**
+   * Prefs observer for Per-user time zone enabled mode.
+   * @private
+   */
+  maybeGetTimeZoneListPerUser_: function() {
+    this.maybeGetTimeZoneList_(true);
+  },
+
+  /**
+   * Prefs observer for Per-user time zone disabled mode.
+   * @private
+   */
+  maybeGetTimeZoneListPerSystem_: function() {
+    this.maybeGetTimeZoneList_(false);
+  },
+
+  /**
    * Converts the C++ response into an array of menu options.
    * @param {!Array<!Array<string>>} timeZones C++ time zones response.
    * @private
    */
   setTimeZoneList_: function(timeZones) {
     this.timeZoneList_ = timeZones.map(function(timeZonePair) {
       return {
         name: timeZonePair[1],
         value: timeZonePair[0],
       };
     });
   },
+
+  /**
+   * Computes visibility of user timezone preference.
+   * @param {?chrome.settingsPrivate.PrefObject} prefUserTimezone
+   *     pref.settings.timezone
+   * @param {boolean} prefResolveValue
+   *     prefs.settings.resolve_timezone_by_geolocation.value
+   * @private
+   */
+  isUserTimeZoneSelectorHidden_: function(prefUserTimezone, prefResolveValue) {
+    return (prefUserTimezone && prefUserTimezone.controlledBy != null) ||
+        prefResolveValue;
+  },
 });