The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/f5e1f6987ccaa8b88d26a0b452c91a6070558b9f

commit f5e1f6987ccaa8b88d26a0b452c91a6070558b9f
Author: Caroline Tice <cmtice@google.com>
Date: Tue May 24 23:06:55 2016

[cbuildbot] Add toolchain waterfall buildbot for next llvm.

This CL creates a new toolchain waterfall bot (release group), to
monitor building ChromeOS with the "next" version of LLVM (to catch
regressions & errors early).

BUG= chromium:614541 
TEST=did run_tests in cbuildbot directory.

Change-Id: Ia1f85f523dd9a919c0d371dd1f899907291bb98e
Reviewed-on: https://chromium-review.googlesource.com/347120
Commit-Ready: Caroline Tice <cmtice@chromium.org>
Tested-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>

[modify] https://crrev.com/f5e1f6987ccaa8b88d26a0b452c91a6070558b9f/cbuildbot/config_dump.json
[modify] https://crrev.com/f5e1f6987ccaa8b88d26a0b452c91a6070558b9f/cbuildbot/waterfall_layout_dump.txt
[modify] https://crrev.com/f5e1f6987ccaa8b88d26a0b452c91a6070558b9f/cbuildbot/config_lib.py
[modify] https://crrev.com/f5e1f6987ccaa8b88d26a0b452c91a6070558b9f/cbuildbot/chromeos_config.py

Bulk verified