import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

layout/reftests/svg/smil/syncbase/changed-interval-change-spec-3.svg

@@ -0,0 +1,22 @@
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:xlink="http://www.w3.org/1999/xlink"
+     class="reftest-wait"
+     onload="
+        document.documentElement.pauseAnimations();
+        document.documentElement.setCurrentTime(1.2);
+        document.getElementById('a').setAttribute('begin', '0s');
+        setTimeAndSnapshot(2, false)">
+  <script xlink:href="../smil-util.js" type="text/javascript"/>
+  <!--
+    Changing the begin spec whilst the syncbase element is active should not
+    cause a change notification to be generated since the begin time is fixed
+    once the element is active.
+   -->
+  <rect width="100" height="100" fill="red">
+    <animate attributeName="y" attributeType="XML" from="0" to="0" id="a"
+      begin="1s" dur="10s"/>
+    <animate attributeName="fill" attributeType="CSS"
+      values="green"
+      begin="a.begin+0.5s" dur="1s"/>
+  </rect>
+</svg>