title: why is the performance of this window.innerheight so bad?
body: <p>I am testing out a test case a friend of mine noticed. He was using window.innerheight in a loop, and there was a very significant drop in the fps.</p>
  
  <p>Here is the link to the jsperf I created to test it <a href="http://jsperf.com/innerheight" rel="nofollow">http://jsperf.com/innerheight</a></p>
  
  <p>The only explanation I can come up with is that this is a getter, and calculates the actual height, on every call. Is that right? Any documentation where I can verify this?</p>