The Tor Browser / file revision

 <svg xmlns="http://www.w3.org/2000/svg"

      class="reftest-wait">

   <!-- Test to be sure that a zero-sized-in-one-dimension viewBox doesn't

        make us fail assertions. -->

   <script>

     document.addEventListener("MozReftestInvalidate", waitAndFinish, false);

     function waitAndFinish() {

       // Sadly, MozReftestInvalidate fires sooner than PaintPattern here, so

       // we need to wait a little bit to give PaintPattern a chance to hit

       // this bug.

       setTimeout(finish, 100);

     }

     function finish() {

       document.documentElement.removeAttribute("class");

     }

   </script>

   <pattern id="test" viewBox="0 0 1 0">

     <rect/>

   </pattern>

   <rect width="200" height="200" fill="url(#test)"/>

 </svg>