MD Settings: clarify "controlled by" logic

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 button;
 
   /** @type {!chrome.settingsPrivate.PrefObject} */
   var pref = {
     key: 'test',
     type: chrome.settingsPrivate.PrefType.BOOLEAN,
     value: true
   };
 
   setup(function() {
     PolymerTest.clearBody();
     button = document.createElement('controlled-button');
     button.pref = pref;
     document.body.appendChild(button);
   });
 
   test('disables when pref is managed', function() {
-    button.set('pref.policyEnforcement',
-               chrome.settingsPrivate.PolicyEnforcement.ENFORCED);
+    button.set('pref.enforcement', chrome.settingsPrivate.Enforcement.ENFORCED);
     Polymer.dom.flush();
     assertTrue(button.$$('paper-button').disabled);
 
     var indicator = button.$$('cr-policy-pref-indicator');
     assertTrue(!!indicator);
     assertGT(indicator.clientHeight, 0);
 
-    button.set('pref.policyEnforcement', undefined);
+    button.set('pref.enforcement', undefined);
     Polymer.dom.flush();
     assertFalse(button.$$('paper-button').disabled);
     assertEquals(0, indicator.clientHeight);
   });
 });