UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36

Steps to reproduce the problem:
<style>.class:hover { color: red; }</style>
<div id="id">TEST</div>
<script>
  setTimeout(function(){
    document.getElementById('id').className = 'class';
  });
</script>

What is the expected behavior?
Hovering the div should change its color to red.

What went wrong?
The class is added, but the CSS for `:hover` doesn't apply. Removing `setTimeout()` wrapper seems to fix it.

Did this work before? N/A 

Chrome version: 62.0.3202.94  Channel: stable
OS Version: 
Flash Version: Shockwave Flash 27.0 r0