[autotest] Add test_retry field to afe_jobs table

Does what it says on the tin.

CQ-DEPEND=If8134fe263bb33ee5d52bc92e78faee05388b239

BUG=chromium-os:37158
TEST=database/migrate.py sync, ensure that jobs can still be viewed in
afe. Ensure that new column exists and is zeroed out for all jobs
already in db. Kick off a smoke suite and ensure that it runs.

Change-Id: I0790d60d7c86d9278507b46ae1579a7b72b20c5a
Reviewed-on: https://gerrit.chromium.org/gerrit/44427
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Queue: Scott Zawalski <scottz@chromium.org>
Tested-by: Scott Zawalski <scottz@chromium.org>
diff --git a/frontend/afe/rpc_interface.py b/frontend/afe/rpc_interface.py
index 57eea88..73b4a58 100644
--- a/frontend/afe/rpc_interface.py
+++ b/frontend/afe/rpc_interface.py
@@ -33,7 +33,6 @@
 
 import datetime
 import common
-from autotest_lib.client.common_lib import control_data
 from autotest_lib.client.common_lib import error
 from autotest_lib.frontend.afe import models, model_logic, model_attributes
 from autotest_lib.frontend.afe import control_file, rpc_utils
@@ -502,7 +501,8 @@
                timeout=None, max_runtime_mins=None, run_verify=True,
                email_list='', dependencies=(), reboot_before=None,
                reboot_after=None, parse_failed_repair=None, hostless=False,
-               keyvals=None, drone_set=None, image=None, parent_job_id=None):
+               keyvals=None, drone_set=None, image=None, parent_job_id=None,
+               test_retry=0):
     """\
     Create and enqueue a job.
 
@@ -534,7 +534,8 @@
     @param drone_set The name of the drone set to run this test on.
     @param image OS image to install before running job.
     @param parent_job_id id of a job considered to be parent of created job.
-
+    @param test_retry: Number of times to retry test if the test did not
+                       complete successfully. (optional, default: 0)
 
     @returns The created Job id number.
     """