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

chrome/test/data/webui/settings/controlled_button_tests.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.
 
 suite('controlled button', function() {
   /** @type {ControlledButtonElement} */
   var controlledButton;
 
   /** @type {!chrome.settingsPrivate.PrefObject} */
   var uncontrolledPref = {
@@ skipping 22 matching lines @@
     Polymer.dom.flush();
   });
 
   test('controlled prefs', function() {
     assertFalse(controlledButton.$$('paper-button').disabled);
     assertFalse(!!controlledButton.$$('cr-policy-pref-indicator'));
 
     controlledButton.pref = extensionControlledPref;
     Polymer.dom.flush();
     assertTrue(controlledButton.$$('paper-button').disabled);
-    assertFalse(!!controlledButton.$$('cr-policy-pref-indicator'));
+    assertTrue(!!controlledButton.$$('cr-policy-pref-indicator'));
 
     controlledButton.pref = policyControlledPref;
     Polymer.dom.flush();
     assertTrue(controlledButton.$$('paper-button').disabled);
     var indicator = controlledButton.$$('cr-policy-pref-indicator');
     assertTrue(!!indicator);
     assertGT(indicator.clientHeight, 0);
 
     controlledButton.pref = uncontrolledPref;
     Polymer.dom.flush();
     assertFalse(controlledButton.$$('paper-button').disabled);
     assertFalse(!!controlledButton.$$('cr-policy-pref-indicator'));
   });
 });