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

chrome/browser/resources/settings/controls/settings_boolean_control_behavior.js

 // Copyright 2016 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
  * A behavior to help controls that handle a boolean preference, such as
  * checkbox and toggle button.
  */
 
@@ skipping 106 matching lines @@
       value = value != this.numericUncheckedValue;
 
     return this.inverted ? !value : !!value;
   },
 
   /**
    * @return {boolean} Whether the checkbox should be disabled.
    * @private
    */
   controlDisabled_: function() {
-    return this.disabled || this.isPrefPolicyControlled();
+    return this.disabled || this.isPrefEnforced();
   },
 };
 
 /** @polymerBehavior */
 var SettingsBooleanControlBehavior = [
   CrPolicyPrefBehavior,
   PrefControlBehavior,
   SettingsBooleanControlBehaviorImpl,
 ];