Blink gardening: rebase expectation for mouseover-mouseout.html

TBR=enne@chromium.org
NOTRY=true
BUG=N/A

Review URL: https://codereview.chromium.org/26441002

git-svn-id: svn://svn.chromium.org/blink/trunk@159096 bbb929c8-8fbe-4397-9dbb-9b2b20218538