20 lines
544 B
HTML
20 lines
544 B
HTML
<!DOCTYPE html>
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<div id="main">
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<svg viewBox="0 0 10 10">
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<defs>
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<circle id="myCircle" cx="5" cy="5" r="4" stroke="blue" />
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</defs>
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<use id="circle" href="#myCircle" fill="green" />
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</svg>
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</div>
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<script>
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const observer = new PerformanceObserver(list => {
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const fcp = list.getEntriesByName("first-contentful-paint");
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if (!fcp.length)
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return;
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// Message the parent when FCP has been reached.
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parent.postMessage("GotFCP", '*');
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});
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observer.observe({ type: "paint", buffered: true });
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</script>
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