This reverts commit 1d493d31.

Reason for revert: Fails on clusterfuzz:
https://crbug.com/1024241

Original change's description:
> [foozzie] Refactor command abstraction
> 
> This moves code for running d8 into its own class. No functional
> changes intended.
> 
> No-Try: true
> Bug: chromium:1023091
> Change-Id: I7cbfeebd2911dc758322f89cf93666550f2956d9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1906378
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Reviewed-by: Tamer Tas <tmrts@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#64928}

TBR=machenbach@chromium.org,tmrts@chromium.org,almuthanna@google.com,liviurau@chromium.org

Change-Id: I22aede0d2c8bd3cde48c45f4663b43caa4d60b65
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1023091,chromium:1024241
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1914208Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64933}