The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/eff017a4d477bf241b86e97cad4b1b513c7c7199

commit eff017a4d477bf241b86e97cad4b1b513c7c7199
Author: Roberto Carrillo <robertocn@google.com>
Date: Sat Jun 23 01:17:50 2018

[Findit] Deprecate the use of `force_buildbot`.

The only remaining use for force_buildbot was to get the mastername
property to use when triggering tryjobs on luci through the
findit_variable builder.

It turns out that for that case we can use the waterfall mastername
instead, doing away with the extra parameter.

R=chanli,stgao

Bug:  853905 
Change-Id: I0e536359dfef607cc97154a60b7a78af7eda81d0
Reviewed-on: https://chromium-review.googlesource.com/1105126
Commit-Queue: Roberto Carrillo <robertocn@chromium.org>
Reviewed-by: Shuotao Gao <stgao@chromium.org>
Reviewed-by: Chan Li <chanli@chromium.org>

[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/compile_failure/test/compile_try_job_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/pipelines/test_failure/test/run_test_try_job_pipeline_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/test/try_job_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/compile_failure/compile_try_job.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/parameters.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/test/build_ahead_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/waterfall/test/waterfall_config_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/pipelines/compile_failure/test/run_compile_try_job_pipeline_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/pipelines/test_failure/test/start_test_try_job_pipeline_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/build_ahead.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/test_failure/test/test_try_job_test.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/try_job.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/waterfall/waterfall_config.py
[modify] https://crrev.com/eff017a4d477bf241b86e97cad4b1b513c7c7199/appengine/findit/services/test_failure/test_try_job.py