Context here:
1. The findit/chromium/test.py recipe already runs selected tests in _parallel_ Swarming tasks if the step (like browser_tests) is configured with multiple tasks.
2. For a base/test/launcher-based gtest binary (like browser_tests), we've made it possible to run a test N times in a _single_ Swarming task with these flags:
    --gtest_filter=AppMenuControllerTest.RecentTabsFavIcon --gtest_repeat=100 --test-launcher-retry-limit=0 --gtest_also_run_disabled_tests

The specific missing parts here are:
1. How to pass the flags  "--gtest_repeat=100 --test-launcher-retry-limit=0 --gtest_also_run_disabled_tests" from the recipe, into recipe_modules/chromium_tests, all the way down to recipe_modules/swarming, and then send them over the wire to Swarming sever ?
2. How to retrieve the number of passed/failed runs among the 100 iteration? We wanted to calculate the pass rate or flakiness.