[autotest] Add stats reporting to shard client.
This adds performance and error statistics to shard client:
- Counter how often client was started, so restarts can be seen
- Number of uncaught exceptions, so sudden failures can be seen
- Number of jobs and hosts persisted/heartbeat
- timer on heartbeat and ticks
BUG=None
TEST=Ran suites.
Change-Id: Id0eda7158e002a8d4c708dea1d5944f5a36a8a2e
Reviewed-on: https://chromium-review.googlesource.com/220000
Tested-by: Jakob Jülich <jakobjuelich@chromium.org>
Reviewed-by: Prashanth B <beeps@chromium.org>
Commit-Queue: Jakob Jülich <jakobjuelich@chromium.org>
1 file changed