1 files changed, 29 insertions, 0 deletions
diff --git a/layout/reftests/css-animations/reframe-and-animation-starts-at-the-same-time.html b/layout/reftests/css-animations/reframe-and-animation-starts-at-the-same-time.html
new file mode 100644
index 0000000000..325236b2a7
--- /dev/null
+++ b/layout/reftests/css-animations/reframe-and-animation-starts-at-the-same-time.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<style>
+@keyframes anim {
+  from { background-color: rgb(255, 255, 255); }
+  to { background-color: rgb(255, 255, 255); }
+}
+#target::before {
+  content: 'initial';
+  background-color: rgb(0, 0, 0);
+  height: 100px;
+  width: 100px;
+  position: absolute;
+}
+#target.hover::before{
+  content: '';
+  animation: anim 100s steps(1, start);
+}
+</style>
+<div id="target"></div>
+<script>
+window.addEventListener("load", () => {
+  target.className = 'hover';
+  target.addEventListener('animationstart', () => {
+    document.documentElement.classList.remove('reftest-wait');
+  });
+});
+</script>
+</html>