Fix compilation issue

R=jochen@chromium.org, vollick@chromium.org
TBR=jochen@chromium.org
BUG=

Review URL: https://codereview.chromium.org/74793008

git-svn-id: svn://svn.chromium.org/blink/trunk@162205 bbb929c8-8fbe-4397-9dbb-9b2b20218538