periodic_scheduler: move timeout value to the jobs themselves

Rather than clamp the runtime of the job to 5 minutes, let the job
declare its max timeout value.  Some jobs want to run for more than
5 minutes (like crash_sender).

BUG=chromium:377981
TEST=`./periodic_scheduler_unittest` passes
CQ-DEPEND=CL:201404

Change-Id: If411bf01e96007ee8a4a83e144f5b8306c48103c
Reviewed-on: https://chromium-review.googlesource.com/201719
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
2 files changed