samples being discarded

 - Passed in as CpuProfilingOptions parameter, client is responsible for
determining if function is still safe to execute. Includes unit tests

 - Client (blink) side CR: https://chromium-review.googlesource.com/c/chromium/src/+/2649617,
 - Client (blink) side CR requires this to be pushed prior to it being pushed

Change-Id: I3ef4640186115d4e14c1b73f902c889c776e310f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2652206
Commit-Queue: Nicolas Dubus <nicodubus@fb.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72794}