This method introduces an inherent race because it allows changing
global static flag variables from concurrently running Isolates (or
Workers). Since there are not too many use-cases left, the method in
question can be removed entirely.

R=hpayer@chromium.org

Change-Id: I9798730dd775b04f0bc83f18ed5982672e76e5d5
Reviewed-on: https://chromium-review.googlesource.com/1186731Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55392}