We've gathered sufficient data, so the use counter can now be removed
again.

The use counter was originally added here:

- V8 CL: https://chromium-review.googlesource.com/c/v8/v8/+/1718145
- Chromium CL: https://chromium-review.googlesource.com/c/chromium/src/+/1718367

The Chromium plumbing was removed here:
https://chromium-review.googlesource.com/c/chromium/src/+/1839851

BUG=v8:9551

Change-Id: I829a0fe34d9ebade1403cb4d1c0b9c997f125074
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1844774Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64124}