This reverts commit 8c359f64.

Reason for revert: Tentative revert for ASAN breakage

Original change's description:
> [zone] Keep one page when we Zone::Reset for reuse
> 
> Change-Id: I50c6124d3da5b35d4156c066f38d10d2dc966567
> Reviewed-on: https://chromium-review.googlesource.com/c/1349246
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#57793}

TBR=ishell@chromium.org,verwaest@chromium.org

Change-Id: Iff319b5f0ad1a65b1171d219a02a4a75d33910bd
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/1349248Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57797}