Unregister with push service and SW database when permission is lost.

chrome/test/data/push_messaging/push_test.js

 // Copyright 2014 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.
 
 'use strict';
 
 var resultQueue = new ResultQueue();
 var pushRegistration = null;
 
 // Sends data back to the test. This must be in response to an earlier
@@ skipping 119 matching lines @@
 
   var unregisterMethodName =
       pushRegistration.unregister ? 'unregister' : 'unsubscribe';
   pushRegistration[unregisterMethodName]().then(function(result) {
     sendResultToTest('unregister result: ' + result);
   }, function(error) {
     sendResultToTest('unregister error: ' + error.name + ': ' + error.message);
   });
 }
 
+function hasRegistration() {
+  navigator.serviceWorker.ready.then(function(swRegistration) {
+    return swRegistration.pushManager.getSubscription();
+  }).then(function(subscription) {
+    sendResultToTest(subscription ? 'true - registered'
+                                  : 'false - not registered');
+  }).catch(sendErrorToTest);
+}
+
 addEventListener('message', function(event) {
   var message = JSON.parse(event.data);
   if (message.type == 'push')
     resultQueue.push(message.data);
 }, false);