- Cleanup includes, fix typo, fix qualifiers.
- Fix getter names of MarkerBase when only exposed for testing.

Bug: chromium:1056170
Change-Id: Ibcb0f62414c9c865fa98e6d2b2c9b150aa2a361f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2281004
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68678}