This allows us to see from a trace how long operations took that are
captured by timer metrics.
Example log entry on push:
[2018-08-29 10:28:37,080] [ReceiveCommits-1] TRACE com.google.gerrit.metrics.Timer0.Context : http/server/rest_api/change_json/to_change_info_latency took 24ms [CONTEXT forced=true RECEIVE_ID="foo-1535531316769-7edf2a7b" TRACE_ID="1535531316773-7edf2a7b" ]
Change-Id: Ib0024cce95693d99781aee8a2b78b777c7c4ce3b
Signed-off-by: Edwin Kempin <ekempin@google.com>
eb17f3b410