Fix oilpan build after inspector style sheet changes.

TBR=vsevik@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/196423025

git-svn-id: svn://svn.chromium.org/blink/trunk@169553 bbb929c8-8fbe-4397-9dbb-9b2b20218538