The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/b16395c45bc3991c71ed4d8a538b636cb9cbb72c

commit b16395c45bc3991c71ed4d8a538b636cb9cbb72c
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Jun 20 21:46:00 2018

[buildbucket] Rename acl.py to user.py

Delegation token minting will be moved to user.py
and user.py will grow request-level cache for the current user, e.g.
delegation token and a list of accessible buckets.

Bug:  854484 ,  854339 
Change-Id: I8eade6ef8af1bea3f1771904fdf432b0b267ff1c
Reviewed-on: https://chromium-review.googlesource.com/1108181
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/access/api.py
[rename] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/test/user_test.py
[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/v2/test/api_test.py
[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/service.py
[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/swarming/swarmbucket_api.py
[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/api.py
[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/swarming/test/swarmbucket_api_test.py
[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/access/test/api_test.py
[modify] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/test/service_test.py
[rename] https://crrev.com/b16395c45bc3991c71ed4d8a538b636cb9cbb72c/appengine/cr-buildbucket/user.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/6d32cf17e15b226a257fb4f86f2698f159ed9396

commit 6d32cf17e15b226a257fb4f86f2698f159ed9396
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Jun 20 22:31:01 2018

[buildbucket] Add per-request caching on accessible buckets

We don't have a python lib for per-request or process caching, so roll our
own, scoped down to the current identity in the current request, based on
threading.Local. It caches a future.

Will be used for delegation cache too.

Bug:  854339 ,  854484 
Change-Id: I495f4ecec768c078a06f10c4e23eedcdf3ef7bd9
Reviewed-on: https://chromium-review.googlesource.com/1108387
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/6d32cf17e15b226a257fb4f86f2698f159ed9396/appengine/cr-buildbucket/swarming/test/swarmbucket_api_test.py
[modify] https://crrev.com/6d32cf17e15b226a257fb4f86f2698f159ed9396/appengine/cr-buildbucket/user.py
[modify] https://crrev.com/6d32cf17e15b226a257fb4f86f2698f159ed9396/appengine/cr-buildbucket/test/user_test.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/61dfdea50614089edc72a52897d7abbb2e93b349

commit 61dfdea50614089edc72a52897d7abbb2e93b349
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Jun 20 23:39:21 2018

[buildbucket] Move delegation token minting to user.py

Move delegation token minting from swarming.py to user.py and add per-request
caching.

Also, in _get_or_create_cached_future ensure we are not waiting on a future
that was created in a different ndb context.

Bug:  854339 
Change-Id: I87ec29b4dc6849f3976b1fce5dce1e63a2e36aee
Reviewed-on: https://chromium-review.googlesource.com/1108498
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/61dfdea50614089edc72a52897d7abbb2e93b349/appengine/cr-buildbucket/swarming/swarming.py
[modify] https://crrev.com/61dfdea50614089edc72a52897d7abbb2e93b349/appengine/cr-buildbucket/user.py
[modify] https://crrev.com/61dfdea50614089edc72a52897d7abbb2e93b349/appengine/cr-buildbucket/test/user_test.py