chromium/third_party/blink/web_tests/fast/css/font-size-negative.html

<html>
 <head>
  <title>Negative Font-Size</title>
  <style type="text/css">

    div#test1 {font: normal 10px/1 Helvetica, Arial, sans-serif; font: normal -50px/5 Georgia, serif;}

  </style>
 </head>
 <body>

  <div id="test1">This should be fairly small text, rather than huge, it should also be set in sans-serif rather than serif.</div>

 </body>
</html>