The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/e39bcc0e824e5cdd6918c4ef8a331f7f11885c0c

commit e39bcc0e824e5cdd6918c4ef8a331f7f11885c0c
Author: Sharu Jiang <katesonia@google.com>
Date: Fri Aug 18 20:02:30 2017

[Predator] Fix bug of not showing regression ranges for some testcases.

If predator failed to parse the stacktrace of a testcase, the returned result is None, in this case, we will set ``has_regression_range`` to False, which is incorrect.

Bug:  754828 
Change-Id: Ic4f738fa2b712d781244e0dd73baeaed2a950478
Reviewed-on: https://chromium-review.googlesource.com/612214
Commit-Queue: Sharu Jiang <katesonia@chromium.org>
Reviewed-by: Shuotao Gao <stgao@chromium.org>

[modify] https://crrev.com/e39bcc0e824e5cdd6918c4ef8a331f7f11885c0c/appengine/predator/app/frontend/handlers/result_feedback.py
[modify] https://crrev.com/e39bcc0e824e5cdd6918c4ef8a331f7f11885c0c/appengine/predator/app/frontend/handlers/test/dashboard_test.py
[modify] https://crrev.com/e39bcc0e824e5cdd6918c4ef8a331f7f11885c0c/appengine/predator/app/frontend/handlers/test/result_feedback_test.py
[modify] https://crrev.com/e39bcc0e824e5cdd6918c4ef8a331f7f11885c0c/appengine/predator/app/common/crash_pipeline.py
[modify] https://crrev.com/e39bcc0e824e5cdd6918c4ef8a331f7f11885c0c/appengine/predator/app/frontend/handlers/dashboard.py

Assuming this is fixed based on c#1. Please reopen if this is incorrect.