[MD settings] show icon when content settings are controlled by an extension

chrome/browser/resources/settings/controls/settings_input.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-input` is a single-line text field for user input associated
  * with a pref value.
  */
 Polymer({
@@ skipping 105 matching lines @@
       this.set('pref.value', this.value);
     }
   },
 
   /**
    * @param {boolean} disabled
    * @return {boolean} Whether the element should be disabled.
    * @private
    */
   isDisabled_: function(disabled) {
-    return disabled || this.isPrefPolicyControlled();
+    return disabled || this.isPrefEnforced();
   },
 });