MD Settings: Date and Time page, part 2/3

chrome/browser/resources/settings/controls/settings_dropdown_menu.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.
 
 /**
  * The |name| is shown in the gui.  The |value| us use to set or compare with
  * the preference value.
  * @typedef {{
  *   name: string,
  *   value: (number|string)
@@ skipping 84 matching lines @@
       return;
 
     var prefValue = this.pref.value;
     var option = this.menuOptions.find(function(menuItem) {
       return menuItem.value == prefValue;
     });
 
     // Need to wait for the dom-repeat to render, before assigning a value to
     // |selected_|, otherwise select#value is not populated correctly.
     this.async(function() {
-      this.selected_ = option == undefined ?
+      var newSelected = option == undefined ?
           this.notFoundValue_ :
           Settings.PrefUtil.prefToString(assert(this.pref));
+
+      // Ensure Polymer recognizes that selected_ changes.
+      if (newSelected == this.selected_)
+        this.selected_ = '';

[stevenjb, 2016/10/21 20:16:40]

Eww. Can we do:
if( == )
  this.notifyPath('selected_');
else
  this.selected_ = newSelected
?

[michaelpg, 2016/10/25 00:35:15]

Found a correct-er fix and rebased this patch on that one.

+      this.selected_ = newSelected;
     }.bind(this));
   },
 
   /**
    * @param {string} selected
    * @return {boolean}
    * @private
    */
   isSelectedNotFound_: function(selected) {
     return this.menuOptions.length > 0 && selected == this.notFoundValue_;
   },
 
   /**
    * @return {boolean}
    * @private
    */
   shouldDisableMenu_: function() {
     return this.disabled || this.menuOptions === null ||
         this.menuOptions.length == 0;
   },
 });