Here are some uses of the new `Field` component without a placeholder:  The design for input validation says: <img width="398" alt="2019-01-24 at 11 42" src="https://user-images.githubusercontent.com/279572/51697322-2883e500-1fcd-11e9-898b-b0020ab6083b.png"> The label should still be inside the input, since it is unfocused with no value.