[users at bb.net] Gathering and displaying build time statistics on buildbot?

[Dan Kegel]

Hi!  I see that Buildbot has metrics and statistics things:
http://docs.buildbot.net/latest/manual/cfg-global.html#metrics-options
http://docs.buildbot.net/latest/manual/cfg-global.html#statistics-service
but there seems to be no user-story-oriented guide about how to use them
to e.g. measure how long a particular builder (or all builders) takes
and display a histogram showing its median and 90th percentile durations.

The closest I found was
https://github.com/buildbot/buildbot/pull/1725
https://gist.github.com/prasoon2211/cbe93436acc436be61c9
http://trac.buildbot.net/ticket/2461
http://trac.buildbot.net/ticket/3350

What is the state of the art here on branch eight?  (I'm at the tip of
eight now.  Could move to nine if it makes this easier.)