Revert of Oilpan: Build fix after r176830 (https://codereview.chromium.org/355633002/)

Reason for revert:
because it doesn't compile

Original issue's description:
> Oilpan: Build fix after r176830
> 
> TBR=wibling@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=176832

TBR=wibling@chromium.org,oilpan-reviews@chromium.org,haraken@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/341303005

git-svn-id: svn://svn.chromium.org/blink/trunk@176834 bbb929c8-8fbe-4397-9dbb-9b2b20218538