The checked condition now more precisely corresponds to the actual
ineffective GC detection heuristic.

Change-Id: I727932c76ff3183e7b038437eefba564c9778ff7
Reviewed-on: https://chromium-review.googlesource.com/997634Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52509}