Revert of [gn] Fix valgrind config (patchset #1 id:1 of https://codereview.chromium.org/2109403002/ )

Reason for revert:
Breaks...

Original issue's description:
> [gn] Fix valgrind config
>
> BUG=chromium:474921
> NOTRY=true
> NOTREECHECKS=true
> TBR=vogelheim@chromium.org, jochen@chromium.org
>
> Committed: https://crrev.com/e97c990a2b1fd0b5b90832a7f182daa25fee8291
> Cr-Commit-Position: refs/heads/master@{#37418}

TBR=vogelheim@chromium.org,jochen@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:474921

Review-Url: https://codereview.chromium.org/2109423002
Cr-Commit-Position: refs/heads/master@{#37419}