The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra.git/+/3b1a71cedd4d149ed646ce175b51ee03fd9908ee

commit 3b1a71cedd4d149ed646ce175b51ee03fd9908ee
Author: chanli <chanli@chromium.org>
Date: Fri Oct 28 02:29:56 2016

[Findit] Modify Findit API to return more information to Sheriff-O-Matic.

1. Add a flag (is_flaky_test) to mark if the result is for flaky test.
2. Add try_job_status.
3. Add confidence score for each suspected_cl.
4. Add analysis_approach for each suspected_cl.

BUG= 609240 ,  655234 

Review-Url: https://codereview.chromium.org/2425853005

[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/findit_api.py
[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/handlers/build_failure.py
[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/handlers/test/build_failure_test.py
[add] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/model/test/wf_suspected_cl_test.py
[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/model/wf_suspected_cl.py
[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/test/findit_api_test.py
[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/waterfall/build_util.py
[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/waterfall/suspected_cl_util.py
[modify] https://crrev.com/3b1a71cedd4d149ed646ce175b51ee03fd9908ee/appengine/findit/waterfall/test/suspected_cl_util_test.py