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diff --git a/testing/web-platform/tests/largest-contentful-paint/observe-text.html b/testing/web-platform/tests/largest-contentful-paint/observe-text.html
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index 0000000000..5d0244b7e3
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+++ b/testing/web-platform/tests/largest-contentful-paint/observe-text.html
@@ -0,0 +1,42 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Largest Contentful Paint: observe text.</title>
+<body>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style>
+p {
+  font-size: 12px;
+}
+</style>
+<script>
+  async_test(function (t) {
+    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
+    let beforeRender;
+    const observer = new PerformanceObserver(
+      t.step_func_done(function(entryList) {
+        assert_equals(entryList.getEntries().length, 1);
+        const entry = entryList.getEntries()[0];
+        assert_equals(entry.entryType, 'largest-contentful-paint');
+        assert_greater_than_equal(entry.renderTime, beforeRender);
+        assert_greater_than_equal(performance.now(), entry.renderTime);
+        assert_approx_equals(entry.startTime, entry.renderTime, 0.001,
+          'startTime should be equal to renderTime to the precision of 1 millisecond.');
+        assert_equals(entry.duration, 0);
+        // Some lower bound: height of at least 12 px.
+        // Width of at least 100 px.
+        // TODO: find a good way to bound text width.
+        assert_greater_than_equal(entry.size, 1200);
+        assert_equals(entry.loadTime, 0);
+        assert_equals(entry.id, 'my_text');
+        assert_equals(entry.url, '');
+        assert_equals(entry.element, document.getElementById('my_text'));
+      })
+    );
+    observer.observe({type: 'largest-contentful-paint', buffered: true});
+    beforeRender = performance.now();
+  }, 'Text element is observable as a LargestContentfulPaint candidate.');
+</script>
+
+<p id='my_text'>This is important text! :)</p>
+</body>