While the dashboard doesn't indicate any problem with this test on Windows (see https://results.webkit.org/?suite=layout-tests&test=http%2Fwpt%2Fcss%2Fcss-animations%2Fstart-animation-001.html), the EWS Windows bot is seeing consistent failures on this test.
Committed r258852: <https://trac.webkit.org/changeset/258852>
TestExpectations have been set, leaving the bug open for a fix.
This test no longer exists.