Hint size of an EditText in XML

I want the hint size of an EditText to be smaller than the real text.

At present I know two solutions:

1. using Html.fromHtml() programmatically, or

2. using <font size=""> in the XML.

However, I don't want to use the first solution because I want the hint to be directly written in my layout XML, while, regarding the second solution, I don't like using the font element because (if I'm not wrong) I cannot explicit the dp measure. Furthermore, the font element is deprecated in HTML5, so it belongs to the "old-style".

I've tried to use the span element with the font-size attribute (from CSS) in my XML, but it doesn't work. Is there any other up-to-date solution?