import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

layout/reftests/svg/smil/syncbase/sandwich-priority-8.svg

@@ -0,0 +1,25 @@
+<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(0);
+      document.getElementById('b').setAttribute('begin', 'a.begin');
+      setTimeAndSnapshot(2, false)">
+  <script xlink:href="../smil-util.js" type="text/javascript"/>
+  <!--
+    Test of animation sandwich priority based on syncbase dependencies.
+
+    Test that we don't filter out a change to the timing model that does not
+    affect the start time of an interval but which DOES affect the dependency
+    chain.
+
+    Given the arrangement below, 'a' will have higher priority, as it is later
+    in the document. However, via script, we make 'b' dependent on 'a' giving
+    it a higher priority whilst preserving the interval times.
+   -->
+  <rect width="100" height="100" fill="orange">
+    <set attributeName="fill" to="green" begin="1s" id="b"/>
+    <set attributeName="fill" to="red"   begin="1s" id="a"/>
+  </rect>
+</svg>