Remove unneeded enable oilpan ifdefs in DocumentMarkerControllerTest.

R=haraken@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/224733005

git-svn-id: svn://svn.chromium.org/blink/trunk@170851 bbb929c8-8fbe-4397-9dbb-9b2b20218538