Rietveld can fetch swarmbucket configs directly from luci-config and automatically discover all builders. This will be a substantial improvement to Rietveld's builder discovery and no chanes to swarmbucket are required.

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra.git/+/fdbf2fbdcbf5fb950444ba5dade2a262e7f5e1fc

commit fdbf2fbdcbf5fb950444ba5dade2a262e7f5e1fc
Author: nodir <nodir@chromium.org>
Date: Tue May 24 21:55:40 2016

swarmbucket: add get_builders api

Rietveld needs to discover new builders. Add swarmbucket API to expose
builders.

R=estaab@chromium.org, vadimsh@chromium.org
BUG= 613647 

Review-Url: https://codereview.chromium.org/2005333002

[modify] https://crrev.com/fdbf2fbdcbf5fb950444ba5dade2a262e7f5e1fc/appengine/cr-buildbucket/api.py
[modify] https://crrev.com/fdbf2fbdcbf5fb950444ba5dade2a262e7f5e1fc/appengine/cr-buildbucket/main.py
[modify] https://crrev.com/fdbf2fbdcbf5fb950444ba5dade2a262e7f5e1fc/appengine/cr-buildbucket/swarming/__init__.py
[add] https://crrev.com/fdbf2fbdcbf5fb950444ba5dade2a262e7f5e1fc/appengine/cr-buildbucket/swarming/swarmbucket_api.py
[add] https://crrev.com/fdbf2fbdcbf5fb950444ba5dade2a262e7f5e1fc/appengine/cr-buildbucket/swarming/test/swarmbucket_api_test.py

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infra/infra_internal.git/+/53e35ae3c3ab0038bfd8b097b019284ac8ad4b3d

commit 53e35ae3c3ab0038bfd8b097b019284ac8ad4b3d
Author: nodir <nodir@google.com>
Date: Fri May 27 02:00:08 2016