MD Settings: Simplify settings-dropdown-menu

chrome/browser/resources/settings/controls/settings_dropdown_menu.html

Index: chrome/browser/resources/settings/controls/settings_dropdown_menu.html
diff --git a/chrome/browser/resources/settings/controls/settings_dropdown_menu.html b/chrome/browser/resources/settings/controls/settings_dropdown_menu.html
index c06182659b71fc3bd33cb84abb182de40f4d5a65..f893b1be8f8705dbaa6034e88f3b2362c4d8cca6 100644
--- a/chrome/browser/resources/settings/controls/settings_dropdown_menu.html
+++ b/chrome/browser/resources/settings/controls/settings_dropdown_menu.html
@@ -3,19 +3,23 @@
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-item/paper-item.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-menu.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
+<link rel="import" href="chrome://md-settings/prefs/selectable_pref_behavior.html">
 
 <dom-module id="settings-dropdown-menu">
   <link rel="import" type="css"
       href="chrome://md-settings/settings_page/settings_page.css">
   <template>
-    <paper-dropdown-menu id="dropdownMenu"
-        label="[[menuLabel_]]" disabled>
-      <paper-menu class="dropdown-content" selected="{{selected_}}">
+    <paper-dropdown-menu id="dropdownMenu" label="[[menuLabel_]]"
+        on-iron-select="onSelect_" disabled="[[disabled]]">

[dschuyler, 2015/11/13 00:11:16]

If we're not disabling the menus while loading, is the disabled necessary?

[michaelpg, 2015/11/13 00:33:08]

I'm exposing disabled as a property, like we do for settings-input and
settings-checkbox. So the host can set a dropdown menu to disabled and that
passes thru to the <paper-dropdown-menu>.

+      <paper-menu class="dropdown-content" selected="{{selected_}}"
+          attr-for-selected="data-value">
         <template is="dom-repeat" items="[[menuOptions]]">
-          <paper-item>[[item.1]]</paper-item>
+          <paper-item data-value$="[[item.0]]">[[item.1]]</paper-item>
         </template>
         <template is="dom-if" if="[[showNotFoundValue_]]">
-          <paper-item>[[i18n('custom')]]</paper-item>
+          <paper-item data-value$="[[notFoundItem_.0]]">
+            [[notFoundItem_.1]]
+          </paper-item>
         </template>
       </paper-menu>
     </paper-dropdown-menu>