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diff --git a/testing/web-platform/tests/css/cssom-view/smooth-scroll-in-load-event.html b/testing/web-platform/tests/css/cssom-view/smooth-scroll-in-load-event.html
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index 0000000000..e515b06710
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+++ b/testing/web-platform/tests/css/cssom-view/smooth-scroll-in-load-event.html
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+<!DOCTYPE html>
+<title>A smooth scroll operation in load event handler isn't omitted</title>
+<meta name="viewport" content="width=device-width,minimum-scale=1,initial-scale=1">
+<link rel="help" href="https://drafts.csswg.org/cssom-view/#concept-smooth-scroll">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/scroll-behavior.js"></script>
+<style>
+  body {
+    margin: 0;
+  }
+  html {
+    overflow: auto;
+  }
+</style>
+<div id="pageContent" style="position: absolute; left: 0; top: 0;"></div>
+<script>
+  window.addEventListener("load", () => {
+    // Expand the page content to make the root scroll container overflowed.
+    pageContent.style.width = (window.innerWidth) * 5 + "px";
+    pageContent.style.height = (window.innerHeight) * 6 + "px";
+
+    promise_test(async () => {
+      document.scrollingElement.scrollTo({
+        left: window.innerWidth,
+        top: window.innerHeight,
+        behavior: "smooth"
+      });
+
+      assert_equals(document.scrollingElement.scrollLeft, 0, "Should not set scrollLeft immediately");
+      assert_equals(document.scrollingElement.scrollTop, 0, "Should not set scrollTop immediately");
+
+      // In the next frame, change something to trigger a paint which might
+      // clobber the smooth scroll operation.
+      await new Promise(resolve => requestAnimationFrame(resolve));
+      pageContent.style.color = "green";
+
+      await waitForScrollEnd(document.scrollingElement);
+
+      assert_equals(document.scrollingElement.scrollLeft, window.innerWidth, "Final value of scrollLeft");
+      assert_equals(document.scrollingElement.scrollTop, window.innerHeight, "Final value of scrollTop");
+    }, `Smooth scroll in load event handler`);
+  });
+</script>