Oilpan: Build fix after r170454

r170454 was almost Oilpan-ready, add missing bits.

R=mvanouwerkerk@chromium.org
BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/219753004

git-svn-id: svn://svn.chromium.org/blink/trunk@170475 bbb929c8-8fbe-4397-9dbb-9b2b20218538