this commit[0] might be what's referenced, and this[1] looks to be the test that Google runs (not sure if this is ran in CI, or only done anecdotally for when performance tests[2] show issues).
0: https://github.com/chromium/chromium/commit/208f274e4bcb5174...
1: https://chromium.googlesource.com/chromiumos/third_party/aut...