mozilla-release/layout/reftests/font-inflation/threshold-input-text-contents-under-1.html

<!DOCTYPE HTML>
<title>font.size.inflation.lineThreshold test</title>
<style>
body { width: 600px; }
body, input { font-size: 12px }
p { margin: 0 }
</style>
<!--
In a 600px container, the minimum font size at 15em per line is 40px.
This means we map 0px-60px into 40px-60px, so 12px gets mapped to 44px.

Further, with a lineThreshold of 100, we need 50 characters of 12px
text to meet the line threshold.
-->
<p>123456789
123456789
<input size="9" value="hi">
123456789
1234567890</p>