@smut can you give me some pointers on where/how to generate this json file?  Could we just modify the format of the existing test_summary.json file, or is that consumed by something else that relies on this specific format?

test_summary.json is only consumed by the build/scripts/slave/recipe_modules/ios/api.py in one place to render the presentation layer (stuff like linking the logs of failed tests), so we can modify it if need be, and then we can update the presentation stuff to match.

The file is generated by the test runner, located at src/ios/build/bots/scripts/test_runner.py.

I am not 100% sure about the details of the format we need to adhere to to use the flakiness dashboard.

Capturing notes from an email thread, so that I have them for later:

You can use a recipe module to do the uploading:
https://cs.chromium.org/chromium/build/scripts/slave/recipe_modules/test_results/api.py?rcl=0&l=11

You'll still need to create the test results json or gtest json file. Both formats are supported. Test results json is simpler and it's mostly described here:
https://www.chromium.org/developers/the-json-test-results-format

The trie encoding is optional and only needed if the test names are redundant and verbose.

You can look at some example files here:
http://test-results.appspot.com/testfile?name=full_results.json

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8eb71cdc6259464bee1640d4acdefb9638088e40

commit 8eb71cdc6259464bee1640d4acdefb9638088e40
Author: rohitrao <rohitrao@chromium.org>
Date: Tue Jan 10 20:15:41 2017

[ios] Updates test_runner.py to output a test results json file.

BUG= 678828 

Review-Url: https://codereview.chromium.org/2619813002
Cr-Commit-Position: refs/heads/master@{#442668}

[modify] https://crrev.com/8eb71cdc6259464bee1640d4acdefb9638088e40/ios/build/bots/scripts/run.py
[modify] https://crrev.com/8eb71cdc6259464bee1640d4acdefb9638088e40/ios/build/bots/scripts/test_runner.py

I'm not sure how to handle all of the various platforms we run on.  Right now the platform gets embedded as part of the test name ("ios_chrome_web_egtests (iPad Air 2 iOS 10.0)"), but that would create a ton of new entries in the test dropdown.

Maybe it would be better to embed the platform as part of the test name or as part of the builder name.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build.git/+/9fbcc9b10e7c93aa94187fdc99e3410f94fcac5f

commit 9fbcc9b10e7c93aa94187fdc99e3410f94fcac5f
Author: smut <smut@google.com>
Date: Thu Jan 26 01:44:07 2017

Upload test results to flakiness dashboard

BUG= 678828 

Change-Id: I3725f5ea58d7986cd98bade6f164ed0b87d3bf0e
Reviewed-on: https://chromium-review.googlesource.com/431112
Commit-Queue: smut <smut@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>

[modify] https://crrev.com/9fbcc9b10e7c93aa94187fdc99e3410f94fcac5f/scripts/slave/recipe_modules/ios/__init__.py
[modify] https://crrev.com/9fbcc9b10e7c93aa94187fdc99e3410f94fcac5f/scripts/slave/recipe_modules/ios/api.py
[modify] https://crrev.com/9fbcc9b10e7c93aa94187fdc99e3410f94fcac5f/scripts/slave/recipe_modules/ios/example.expected/basic.json
[modify] https://crrev.com/9fbcc9b10e7c93aa94187fdc99e3410f94fcac5f/scripts/slave/recipe_modules/ios/example.py
[modify] https://crrev.com/9fbcc9b10e7c93aa94187fdc99e3410f94fcac5f/scripts/slave/recipe_modules/test_results/api.py