title: What is "Document count" counter in Timeline tab of Chrome Dev Toolbar?
body: <p>Could someone explain me what does 'Document count' counter stands for in Timeline tab of Chrome Dev Toolbar?</p>
  
  <p>In my application I'm using iframes and navigate within a set of pages in one of them. Currently 'Document count' counter shows me a range of values 23-32, what doest it stand for?</p>
  
  <p>Thanks in advance.</p>