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diff --git a/testing/web-platform/tests/paint-timing/fcp-only/fcp-ensure-update-the-rendering-step.html b/testing/web-platform/tests/paint-timing/fcp-only/fcp-ensure-update-the-rendering-step.html
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+++ b/testing/web-platform/tests/paint-timing/fcp-only/fcp-ensure-update-the-rendering-step.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<head>
+    <title>
+      Ensure the timing is marked during the `update the rendering` step.
+    </title>
+</head>
+<style>
+    #main {
+        width: 100px;
+        height: 100px;
+        left: 0px;
+        position: relative;
+        top: 0;
+        background-image: url(../resources/circles.png);
+        opacity: 0;
+    }
+
+    #main.contentful {
+        opacity: 0.1;
+    }
+</style>
+<body>
+<script src="../resources/utils.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="main"></div>
+<script>
+setup({"hide_test_state": true});
+async_test(function (t) {
+    assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
+    let fired = false;
+    const main = document.getElementById('main');
+    let animationFrameStamps = [];
+    requestAnimationFrame(function frame(stamp) {
+        animationFrameStamps.unshift(stamp);
+        main.className = "contentful";
+        while (performance.now() - stamp <= 5) {
+          /* Busy-wait */
+        }
+        if(!fired)
+            requestAnimationFrame(frame);
+    });
+    new PerformanceObserver(t.step_func(list=>{
+        for (let entry of list.getEntries()) {
+            if (entry.name == "first-contentful-paint") {
+                fired = true;
+                assert_any(assert_approx_equals, entry.startTime, animationFrameStamps, 1, "One of the past requestAnimationFrame should have the same timestamp as paint entry");
+                t.done();
+            }
+        }
+    })).observe({type: "paint"});
+}, 'The first-contentful-paint timestamp should be same as the last RAF');
+</script>
+</body>
+</html>