Revert of [CQ] Reduce code-coverage experiment factor. (patchset #1 id:1 of https://codereview.chromium.org/1822703002/ )

Reason for revert:
More bots added.

Original issue's description:
> [CQ] Reduce code-coverage experiment factor.
>
> BUG=chromium:568949
> LOG=n
> TBR=kjellander@chromium.org, tandrii@chromium.org
> NOTRY=true
> NOPRESUBMIT=true
>
> Committed: https://crrev.com/76f677fc6d0b147603ddda2d5809086b0d36d900
> Cr-Commit-Position: refs/heads/master@{#34946}

TBR=kjellander@chromium.org,tandrii@chromium.org
BUG=chromium:568949
LOG=n
NOPRESUBMIT=true
NOTRY=true

Review URL: https://codereview.chromium.org/1816283004

Cr-Commit-Position: refs/heads/master@{#35021}