Chrome may send memory measurement requests to multiple renderer
processes at the same time. This may lead to multiple GC happening at
the same time if the processes are idle. Randomization spreads out
the GCs over time to reduce the load on the system.

Bug: chromium:1049093
Change-Id: I5aa67fb07f8a55d0ba769bf823168b35cb3c23cb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2208861
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68472}