communicating server timing data to the client.. Server Timing?

https://gist.github.com/igrigorik/97dfe5ea9b4a85162e25

We had a brief discussion around this at TPAC, but in the context of
extending User Timing. However, having thought about it some more, I'm
thinking this could/should be an extension for Nav and Resource Timing
interfaces... perhaps even a standalone spec?

That said, I'm getting ahead of myself... Curious to hear everyone's
thoughts? Is it worth pursuing further? Am I overlooking any major problems
or gotchas?

ig