Revert of Skip slow tests in non debug too (patchset #1 id:1 of https://codereview.chromium.org/1184923003/)

Reason for revert:
[Sheriff] Needed for reverting:
https://codereview.chromium.org/1175313003

Original issue's description:
> Skip slow tests in non debug too
>
> BUG=N
> LOG=N
> TBR=adamk
>
> Committed: https://crrev.com/17b0f16c760e5b0d51ae87742a864de93b6f4c0b
> Cr-Commit-Position: refs/heads/master@{#29058}

TBR=adamk@chromium.org,arv@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=N

Review URL: https://codereview.chromium.org/1177223004

Cr-Commit-Position: refs/heads/master@{#29066}