Fix DCHECK failure with invalid animation range

Bug: 1422110
Change-Id: Ie6f03f7a3848ffcf15a333db21e7cc757a70f6b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4319646
Reviewed-by: Mustaq Ahmed <mustaq@chromium.org>
Commit-Queue: Kevin Ellis <kevers@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1114583}
diff --git a/scroll-animations/crashtests/invalid-animation-range.html b/scroll-animations/crashtests/invalid-animation-range.html
new file mode 100644
index 0000000..43b23c9
--- /dev/null
+++ b/scroll-animations/crashtests/invalid-animation-range.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Invalid animation range</title>
+<body onload="runTest()">
+  <div id="target"></div>
+</body>
+<script src="../../web-animations/testcommon.js"></script>
+<script>
+  async function runTest() {
+    const anim = target.animate(undefined, {rangeStart: "initial" });
+    await waitForNextFrame();
+    await waitForNextFrame();
+  }
+</script>