M 20 20 h 60 v 60 h -60 Z M 30 30 h 40 v 40 h -40 Z")');
test_valid_value("clip-path",
  'path(nonzero, "M20,20h60 v60 h-60z M30,30 h40 v40 h-40z")',
  'path("M 20 20 h 60 v 60 h -60 Z M 30 30 h 40 v 40 h -40 Z")');
// See https://github.com/w3c/fxtf-drafts/issues/392. If empty path string,
// Blink serializes it as none, but Gecko serializes as path("").
test_valid_value("clip-path", 'path(" ")', ["none", 'path("")']);
test_valid_value("clip-path", 'path(evenodd, "")', ["none", 'path(evenodd, "")']);

// <