Remove CSSPropertyWebkitCursorVisibility from UseCounter

Support for CSSPropertyWebkitCursorVisibility has been removed:
https://chromiumcodereview.appspot.com/14612004

Review URL: https://codereview.chromium.org/563553002

git-svn-id: svn://svn.chromium.org/blink/trunk@181756 bbb929c8-8fbe-4397-9dbb-9b2b20218538