title: jQuery ajax async: false causes a strange warning?
body: <p>In my JS App, i have many Ajax calls with <code>async: false</code>. I am using latest Chrome browser and in my console below warning appears recently.</p>
  
  <blockquote>
    <p>Synchronous XMLHttpRequest on the main thread is deprecated because of
    its detrimental effects to the end user's experience. For more help,
    check <a href="http://xhr.spec.whatwg.org/" rel="noreferrer">http://xhr.spec.whatwg.org/</a>.</p>
  </blockquote>
  
  <p>Now i am trying to change all <code>async: false</code> to <code>async: true</code>. But it causes a lot of error because my app needs to run with <code>async: false</code>. </p>
  
  <p>Is the warning just a bug or something? Can i worry about that or ignore that?</p>