import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

layout/reftests/svg/smil/anim-class-04.svg

@@ -0,0 +1,21 @@
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:xlink="http://www.w3.org/1999/xlink"
+     class="reftest-wait" onload="setTimeAndSnapshot(1, true)">
+  <title>Test animation of the class attribute on "rect" elements</title>
+  <script xlink:href="smil-util.js" type="text/javascript"/>
+  <style type="text/css">
+
+    .start {fill: red; }
+
+  </style>
+
+  <rect width="100%" height="100%" fill="red"/>
+  <rect width="100%" height="100%" class="start">
+    <set attributeName="class" attributeType="XML"
+         to="#ThisIsAnInvalidClassName" begin="0.5s" dur="1s" fill="freeze"/>
+  </rect>
+</svg>