title: google.setOnLoadCallback does not work/does not wait until anything is loaded
body: <p>That's pretty much it, the call seems to do absolutely nothing.</p>
  
  <p>If I debug the page in Chrome, put a breakpoint right after the call to </p>
  
  <pre><code>google.load('visualization', '1.0', { packages: ['corechart', 'bar', 'table'] });
  </code></pre>
  
  <p>and literally wait 5-10 seconds for the loading to finish, then proceed, it is fine. Otherwise, if I let 'setOnLoadCallback' try to do it's thing, it will throw </p>
  
  <blockquote>
    <p>'Uncaught TypeError: Cannot read property 'DataTable' of undefined'</p>
  </blockquote>
  
  <p>The error is thrown on:</p>
  
  <pre><code>var data = new google.visualization.DataTable();
  </code></pre>
  
  <p>Edit:</p>
  
  <p>I should also note that in all examples I've found, when calling</p>
  
  <pre><code>google.setOnLoadCallback(drawChart);
  </code></pre>
  
  <p>All the examples are as above, without including the brackets '()' at the end of the function, i.e.</p>
  
  <pre><code>google.setOnLoadCallback(drawChart());
  </code></pre>
  
  <p>However, the only way it actually works for me, is WITH the brackets, yet there are no examples where people include the  brackets.</p>