title: Android App usage (usagestats) does not show entry of Overlay drawn app like Facebook Messagener Chat head
body: <p>I am trying to capture individual app events in android to get to know the amount of time spet in each app. Most of the time it works fine for regular apps but for app who's screen are drawn as overlay such as facebook chat heads NO entry is shown in usage stats.
  Same is the case for <em>#</em>#4636#<em>#</em> ->  Usage statistics.</p>
  
  <p>Please let me know if there is any way to get overlay app's details.</p>
  
  <p>Thanks in advance!!!</p>