title: Google Maps draw mode measure distance
body: <p>I'm trying to implement "Measure Distance" in google maps v3, something like what we can do in <a href="http://www.google.com/maps" rel="noreferrer">Google Maps Web</a>.</p>
  
  <p><img src="https://i.stack.imgur.com/7soJm.png" alt="Measure Distance"></p>
  
  <p>I wonder if there is a library that implmente this as a drawingMode of DrawingManager.</p>