Revert of Experiment: reduce heap growing factor to investigate OOM impact. (patchset #4 id:60001 of https://codereview.chromium.org/1060533003/)

Reason for revert:
Experiment done.

Original issue's description:
> Experiment: reduce heap growing factor to investigate OOM impact.
>
> This CL will be reverted after getting sufficient data.
> BUG=
>
> Committed: https://crrev.com/8b737395c8fcde35cbfbed6607f767ed48eefc5b
> Cr-Commit-Position: refs/heads/master@{#27804}

TBR=ulan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1085353003

Cr-Commit-Position: refs/heads/master@{#27871}