The observers can use ResetAllocatedObjectSize() to e.g. implement a
growing strategy that resets its limit on this call.

Bug: chromium:1056170
Change-Id: Ib9553e00cc530ff89f44e4258c13d47f0b70568e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2228885Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68205}