title: Web Worker Works but generate error in console
body: <p>I created a Web Worker which works correctly but when I open the chrome Console I see the following error:
  Uncaught TypeError: Failed to execute 'postMessage' on 'Window': 2 arguments required, but only 1 present.</p>
  
  <p>This is the file.js which implements the worker.</p>
  
  <pre><code>    'use strict';
  
  function GetSummaryAsync() {
      //$.getJSON("/api/Summary/GetSummaryAsync", function (response) {
      //    postMessage(response);
      //});
      postMessage('pippo');
  }
  
  GetSummaryAsync();
  setInterval(GetSummaryAsync, 15000);
  </code></pre>
  
  <p>Can someone help me to solve the error?</p>