Fix interleaved server job results leading to parsing error ABORT.

Currently server jobs run through distribute_across_machines are
executed under the root execution context, this causes multiple
server jobs to write their results on top of one another.

I've modified distribute_across_machines to behave more like
parallel_on_machines and parallel_simple by moving the execution
context for each worker into its respective subdirectory.

BUG=none
TEST=http://cautotest:15000/results/53007-dalecurtis/group0

Change-Id: Ia12d26203161abef96a8ffb19b5286afc2f4a039
Reviewed-on: http://gerrit.chromium.org/gerrit/5413
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Reviewed-by: Paul Pendlebury <pauldean@chromium.org>
Tested-by: Dale Curtis <dalecurtis@chromium.org>
1 file changed