Per discussion this will be MasterFlakeAnalysis and Flake that are associated, not FlakeIssue (which is contained within Flake)

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/4367872d7b5468a15a8f798a45cd89dfeed42532

commit 4367872d7b5468a15a8f798a45cd89dfeed42532
Author: Jeffrey Li <lijeffrey@chromium.org>
Date: Wed Nov 14 18:55:56 2018

[Findit] Flake Analyze: Associate Flake with MasterFlakeAnalysis

Part 1 of several changes needed to associate Flake with MasterFlakaAnalysis.

In this change, associate Flake with MasterFlakeAnalysis through FlakeDetection
as Flakes are already created.

Flakes detected through CI failure analysis do not create Flake/FlakeIssues yet,
which will be hooked up in subsequent changes.

Bug: 901048
Change-Id: Id9fbe5cb50ebb37fb1313877596cb6adc4242ad9
Reviewed-on: https://chromium-review.googlesource.com/c/1330878
Commit-Queue: Jeffrey Li <lijeffrey@chromium.org>
Reviewed-by: Chan Li <chanli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#18989}
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/services/test/flake_issue_util_test.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/model/flake/analysis/master_flake_analysis.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/waterfall/flake/test/flake_analysis_service_test.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/pipelines/trigger_flake_analyses_pipeline.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/waterfall/flake/test/initialize_flake_pipeline_test.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/waterfall/flake/initialize_flake_pipeline.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/model/flake/test/flake_test.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/waterfall/flake/flake_analysis_service.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/services/test/apis_test.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/services/apis.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/model/flake/analysis/flake_analysis_request.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/model/flake/flake.py
[modify] https://crrev.com/4367872d7b5468a15a8f798a45cd89dfeed42532/appengine/findit/services/flake_issue_util.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/9f74ecf49d6a03db229a6bc5561457e7efa15a38

commit 9f74ecf49d6a03db229a6bc5561457e7efa15a38
Author: Jeffrey Li <lijeffrey@chromium.org>
Date: Wed Nov 21 01:28:06 2018

[Findit] Flake Analyzer - Associate MasterFlakeAnalysis with Flake detected on CI

After this change, all new MasterFlakeAnalyses should have Flakes associated with
them, regardless of triggering source.

Use the original triggering master, builder, build number, step, test to create
a corresponding Flake entity with normalized step/test names, and store it to
FlakeAnalysisRequest which eventually passes it to MasterFlakeAnalysis. Existing
Flakes are first queried for before creating new ones.

Bug: 901048
Change-Id: Ia776d55d9842be7b1e96c751164b2b75538b30d3
Reviewed-on: https://chromium-review.googlesource.com/c/1336691
Reviewed-by: Chan Li <chanli@chromium.org>
Commit-Queue: Jeffrey Li <lijeffrey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#19113}
[add] https://crrev.com/9f74ecf49d6a03db229a6bc5561457e7efa15a38/appengine/findit/services/test/flake_util_test.py
[add] https://crrev.com/9f74ecf49d6a03db229a6bc5561457e7efa15a38/appengine/findit/services/flake_util.py
[modify] https://crrev.com/9f74ecf49d6a03db229a6bc5561457e7efa15a38/appengine/findit/pipelines/trigger_flake_analyses_pipeline.py