Gardening: remove expectation for fast/transforms/shadows.html on Maveric from TestExpectations

BUG=
TBR=enne, ojan
NOTRY=true

Review URL: https://codereview.chromium.org/268353012

git-svn-id: svn://svn.chromium.org/blink/trunk@173630 bbb929c8-8fbe-4397-9dbb-9b2b20218538