This fixed IncrementalMarkingStepMakesBigProgressWithLargeObjects
and MapRetaining.

Change-Id: I3a91684fa1f0635e94dc1883b105ce8d3381a7d2
Reviewed-on: https://chromium-review.googlesource.com/628416
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47548}