Remove unneeded XP-specific expectation following r160380

TBR=dglazkov@chromium.org
BUG=231880

Review URL: https://codereview.chromium.org/38493002

git-svn-id: svn://svn.chromium.org/blink/trunk@160391 bbb929c8-8fbe-4397-9dbb-9b2b20218538