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+<!DOCTYPE html>
+<title>Layout Instability: parent and overflowing absolute child moved together</title>
+<link rel="help" href="https://wicg.github.io/layout-instability/" />
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/util.js"></script>
+<div id="parent" style="position: relative; width: 100px; height: 100px; background: yellow">
+ <div id="child" style="position: absolute; top: 300px; left: 400px; width: 100px; height: 100px; background: blue"></div>
+</div>
+<script>
+
+promise_test(async () => {
+ const watcher = new ScoreWatcher;
+
+ // Wait for the initial render to complete.
+ await waitForAnimationFrames(2);
+
+ // Modify the position of the div.
+ const parent = document.querySelector("#parent");
+ parent.style.top = '100px';
+
+ // We should track parent and child separately.
+ const expectedScore = computeExpectedScore(100 * (100 + 100), 100) * 2;
+
+ // Observer fires after the frame is painted.
+ assert_equals(watcher.score, 0);
+ await watcher.promise;
+ assert_equals(watcher.score, expectedScore);
+}, 'Parent and overflowing absolute child movement.');
+
+</script>