You can target spin buttons using ::-webkit-inner/outer-spin-button
and than just set opacity
to 1 (spins are always there, but in default they have opacity: 0
).
Code:
<style>
input[type=number]::-webkit-inner-spin-button {
opacity: 1
}
</style>
<input type="number" value="1" min="1" max="999">
Fiddle:
http://jsfiddle.net/dk8fj/