[autotest] Stat number of new jobs per scheduler tick.

Send new hostless, atomic and host-job-assignment counts per
tick as a guage to statsd. This will be useful in figuring
out the expected overhead in querying rdb for a host/job and
designing a sensible host acquisition api.

TEST=Ran it, checked stat keys.
BUG=None.

Change-Id: I4fcc88945af6c6ad41e5df43932e9a9de2991ec6
Reviewed-on: https://chromium-review.googlesource.com/173329
Commit-Queue: Prashanth B <beeps@chromium.org>
Tested-by: Prashanth B <beeps@chromium.org>
Reviewed-by: Dan Shi <dshi@chromium.org>
1 file changed