The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/6ad76be15fa6ea3a4bfb8c82c4a11f26c6265788

commit 6ad76be15fa6ea3a4bfb8c82c4a11f26c6265788
Author: Ting-Yuan Huang <laszio@chromium.org>
Date: Sat Jan 28 00:18:42 2017

cbuildbot: remove 'toolchain-tests' from toolchain builders

There are only 2 tests in toolchain-tests:
1. platform_ToolchainOptions will be moved to bvt-cq.
2. network_VPNConnect is too flaky and is going to be disabled.

BUG= chromium:686348 
TEST=chromeos_config_unittest

Change-Id: I21f931485d0514bd72ebd1e80b83885b88b26e12
Reviewed-on: https://chromium-review.googlesource.com/434101
Commit-Ready: Ting-Yuan Huang <laszio@chromium.org>
Tested-by: Ting-Yuan Huang <laszio@chromium.org>
Reviewed-by: Luis Lozano <llozano@chromium.org>

[modify] https://crrev.com/6ad76be15fa6ea3a4bfb8c82c4a11f26c6265788/cbuildbot/config_dump.json
[modify] https://crrev.com/6ad76be15fa6ea3a4bfb8c82c4a11f26c6265788/cbuildbot/chromeos_config.py

Most of them fail due to timeout or during provisioning.

This is mostly obsolete now.
Builders tehse days break generally because of lack of machines in suite pool.