Revert of [gn] Switch off gyp in runhooks by default (patchset #2 id:20001 of https://codereview.chromium.org/2327033002/ )

Reason for revert:
Broke stuff - need to fix the argument

Original issue's description:
> [gn] Switch off gyp in runhooks by default
>
> This will be synced with an announcement on v8-dev. This
> doesn't affect directly calling gyp in our old Makefiles.
>
> BUG=chromium:474921
> NOTRY=true
>
> Committed: https://crrev.com/94f813e8dcd4ed5a67cede8af0f949009beaa501
> Cr-Commit-Position: refs/heads/master@{#39308}

TBR=jochen@chromium.org,jkummerow@chromium.org,vogelheim@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/2324173002
Cr-Commit-Position: refs/heads/master@{#39309}