Cross-browser INP observation

<div class="atlas"><div class="head"><b>INP · coverage across engines</b><span class="pulse"></span></div><div class="stage"><div class="xinp-row"><b>Engine A</b><div><i id="xinp-a"></i></div><span id="xinp-av">—</span></div><div class="xinp-row"><b>Engine B</b><div><i id="xinp-b"></i></div><span id="xinp-bv">—</span></div><div class="xinp-row"><b>Engine C</b><div><i id="xinp-c"></i></div><span id="xinp-cv">—</span></div><div class="xinp-foot mono" id="xinp-foot">RUM sees three engines</div></div></div>

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let phase=0;const ids=['a','b','c'],values=['112ms','178ms','134ms'];function tick(){ids.forEach((id,i)=>{const on=i<=phase;document.getElementById('xinp-'+id).style.width=on?[44,72,55][i]+'%':'0%';document.getElementById('xinp-'+id+'v').textContent=on?values[i]:'—'});document.getElementById('xinp-foot').textContent=phase===2?'compare by engine, not CrUX alone':'Event Timing sample arrives';phase=(phase+1)%3}tick();setInterval(tick,850)