This reverts commit 1db33e5f.

Reason for revert: {AttributeError} 'Namespace' object has no attribute 'experimental'

Original change's description:
> [browser-stories] gate features behind {experimental} flag
> 
> Performance infra recipes use callstats.py to run web page replays. Split (v8,
> infa, perf-infra) repositories make experimenting with callstats.py hard.
> 
> This CL creates feature gating for simplifying performance infra experiments.
> 
> R=​ulan@chromium.org
> 
> No-Try: true
> Bug: v8:9448
> Change-Id: I2c3e139f4b9d6bce1ea4fdda1a44960d74d7d414
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1690950
> Auto-Submit: Tamer Tas <tmrts@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Tamer Tas <tmrts@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62565}

TBR=ulan@chromium.org,tmrts@chromium.org

Change-Id: If40be01a2edebf0538ad306fa5ded0dfa2aaf147
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9448
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1692922Reviewed-by: Tamer Tas <tmrts@chromium.org>
Commit-Queue: Tamer Tas <tmrts@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62595}