The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/54b7dab83c9bc029a3113e3afc8c19f6f3019e88

commit 54b7dab83c9bc029a3113e3afc8c19f6f3019e88
Author: Paul Hobbs <phobbs@google.com>
Date: Wed Jul 26 23:46:52 2017

test_stages: Make VMTests for pre-cq forgiven.

betty-pre-cq's vm test are currently breaking semi-regularly. Make them
advisory until the problem is solved.

Added an ForgivenVMTestStage stage to test_stages, and made simple_builder use
it for pre-cq configs.

TEST=unit tests pass.
BUG= chromium:748995 

Change-Id: I12e095b1a249e03daf9987b24a56b15e17444522
Reviewed-on: https://chromium-review.googlesource.com/586108
Commit-Ready: Paul Hobbs <phobbs@google.com>
Tested-by: Paul Hobbs <phobbs@google.com>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>

[modify] https://crrev.com/54b7dab83c9bc029a3113e3afc8c19f6f3019e88/cbuildbot/stages/test_stages.py
[modify] https://crrev.com/54b7dab83c9bc029a3113e3afc8c19f6f3019e88/cbuildbot/builders/simple_builders.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/5fed0a54c221a9021d75504dc5a9c4758b9ad52e

commit 5fed0a54c221a9021d75504dc5a9c4758b9ad52e
Author: Paul Hobbs <phobbs@google.com>
Date: Fri Aug 04 02:23:17 2017

simple_builders: Make pre-cq vm tests unforgiving

Pre-cq vm tests were flakey due to  crbug.com/748995 , so we changed vm-tests in pre-cq to be forgiven (using ForgivenVMTestStage). The emergency is over, so we should stop using ForgivenVMTestStage.

BUG= chromium:748995 
TEST=None

Change-Id: I4965d3e5d3339dd8dc8ff97e20ea3854d248fc9c
Reviewed-on: https://chromium-review.googlesource.com/600542
Commit-Ready: Paul Hobbs <phobbs@google.com>
Tested-by: Paul Hobbs <phobbs@google.com>
Reviewed-by: Ningning Xia <nxia@chromium.org>

[modify] https://crrev.com/5fed0a54c221a9021d75504dc5a9c4758b9ad52e/cbuildbot/builders/simple_builders.py