Tolerance was set to 50 microseconds. This is not enough and causes
flaky failures. Tolerance is needed because we record milliseconds and
an empty scope can still take a few milliseconds to create and destroy.

Increasing the tolerance to 500 microseconds should suffice and makes
sense for the test. All expected values are in 10s of milliseconds, so
half a millisecond tolerance should be reasonable.

Bug: v8:11367
Change-Id: I2d284efe5176ec9938b6a378f4b5f1bda0e58781
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2659058
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Auto-Submit: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72426}