title: How to find class by property
body: <p>I'm doing some manipulations at the 'video' class at youtube, like change the currentTime property and read duration property of that class and I had success doing it. But when I go to other sites, sometimes they change the name of 'video' to 'video2' for example, and my code doesn't work in that site. I want to know if there is a easy way to make my code look for classes that have the currentTime property, and than set this as my variable, for example.</p>
  <p>what I can do:</p>
  <pre><code>    var videoClass = document.getElementsByTagName('video');
  </code></pre>
  <p>what I want to do:</p>
  <pre><code>    var videoClass = document.getClassesByProperty('currentTime');
  </code></pre>