Revert of Oilpan: fix build after r171701 (https://codereview.chromium.org/239603006/)

Reason for revert:
[blink gardening] 

This patch is on the top of https://codereview.chromium.org/224733011, which I am going to revert after this reverting.

See the comment of https://codereview.chromium.org/224733011 for the revert.

Original issue's description:
> Oilpan: fix build after r171701
> 
> NOTRY=true
> BUG=340522
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=171724

TBR=oilpan-reviews@chromium.org,haraken@chromium.org,sigbjornf@opera.com
NOTREECHECKS=true
NOTRY=true
BUG=340522

Review URL: https://codereview.chromium.org/239863003

git-svn-id: svn://svn.chromium.org/blink/trunk@171750 bbb929c8-8fbe-4397-9dbb-9b2b20218538