[MD settings] controlled by extension icon on default font size

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

 <link rel="import" href="chrome://resources/html/md_select_css.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
+<link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_pref_behavior.html">
+<link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_pref_indicator.html">
 <link rel="import" href="pref_control_behavior.html">
 <link rel="import" href="../i18n_setup.html">
 <link rel="import" href="../prefs/pref_util.html">
 <link rel="import" href="../settings_shared_css.html">
 <link rel="import" href="../settings_vars_css.html">
 
 <dom-module id="settings-dropdown-menu">
   <template>
     <style include="settings-shared md-select">
+      :host {
+        display: inline-flex;
+      }
+
+      cr-policy-pref-indicator,
+      select {
+        -webkit-margin-start: var(--checkbox-spacing);

[dschuyler, 2017/03/02 19:31:37]

It could be argued that --checkbox-spacing should get a different name since
it's used outside of checkboxes (here and elsewhere). It's really more of a
generic horizontal spacing within a control (such as a checkbox). If desired,
I'd like to do that post this CL.

Other uses:
https://cs.chromium.org/search/?q=checkbox-spacing+file:src/chrome&type=cs

[tommycli, 2017/03/03 21:26:27]

Sounds good, in followup CL sounds good.

+      }
+
       /* Hide "Custom" value when unselectable. */
       option:disabled {
         display: none;
       }
     </style>
+    <template is="dom-if" if="[[pref.controlledBy]]" restamp>
+      <cr-policy-pref-indicator pref="[[pref]]"></cr-policy-pref-indicator>
+    </template>
     <div class="md-select-wrapper">
       <select class="md-select" id="dropdownMenu" on-change="onChange_"
-          disabled="[[shouldDisableMenu_(disabled, menuOptions)]]">
+          disabled="[[shouldDisableMenu_(disabled, menuOptions, pref.*)]]">
         <template is="dom-repeat" items="[[menuOptions]]">
           <option value="[[item.value]]">[[item.name]]</option>
         </template>
         <option value="[[notFoundValue_]]"
             disabled="[[!showNotFoundValue_(menuOptions, pref.value)]]">
           $i18n{custom}
         </option>
       </select>
       <span class="md-select-underline"></span>
     </div>
   </template>
   <script src="settings_dropdown_menu.js"></script>
 </dom-module>