In landing https://chromium-review.googlesource.com/c/chromium/src/+/1041152,

I wanted to write some tests to ensure that UMAs are correctly recorded. However, there is no way to add such tests.

Currently, I'm trying two different approaches:

1) Local unit tests (JUnit / Robolectric)
2) Instrumentation test for glue layer (with a separate android_library to access system apis).