The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/f71480e9292a9cb36af38a55f4e35c86c0b80139

commit f71480e9292a9cb36af38a55f4e35c86c0b80139
Author: Jeffrey Li <lijeffrey@chromium.org>
Date: Thu Sep 14 18:32:41 2017

[Findit] Flake Analyzer - Make rerun required parameter for try jobs

Bug:  765045 
Change-Id: I17a6d92cb15df85448ae831f10fdcb5aa5cadbf0
Reviewed-on: https://chromium-review.googlesource.com/666234
Commit-Queue: Jeffrey Li <lijeffrey@chromium.org>
Reviewed-by: Chan Li <chanli@chromium.org>
Reviewed-by: Shuotao Gao <stgao@chromium.org>

[modify] https://crrev.com/f71480e9292a9cb36af38a55f4e35c86c0b80139/appengine/findit/waterfall/flake/test/initialize_flake_try_job_pipeline_test.py
[modify] https://crrev.com/f71480e9292a9cb36af38a55f4e35c86c0b80139/appengine/findit/waterfall/flake/recursive_flake_try_job_pipeline.py
[modify] https://crrev.com/f71480e9292a9cb36af38a55f4e35c86c0b80139/appengine/findit/waterfall/flake/test/recursive_flake_try_job_pipeline_test.py