OkHttp transport has high latency

[ejona86]

For some unknown reason, OkHttp transport regressed in performance dramatically, considering it used to be beating Netty. Unfortunately we don't know when. We need to do some profiling and figure out where the latency is coming from.

[madongfly]

@ejona86 Where does the latency data come from? I'd like to take a look.

[ejona86]

@madongfly, from the Caliper TestServiceBenchmarks.java test internally. It's not on GitHub.