onFID = (onReport) => {
  const visibilityWatcher = getVisibilityWatcher.getVisibilityWatcher();
  const metric = initMetric.initMetric('FID');
  // eslint-disable-next-line prefer-const
  let report;

  const handleEntry = (entry) => {
    // Only report if the page wasn't hidden prior to the first input.
    if (entry.startTime < visibilityWatcher.firstHiddenTime) {
      metric.value = entry.processingStart - entry.startTime;
      metric.entries.push(entry);
      report(true);
    }
  };

  const handleEntries = (entries) => {
    (entries ).forEach(handleEntry);
  };

  const po = observe.observe('first-input', handleEntries);
  report = bindReporter.bindReporter(onReport, metric);

  if (po) {
    onHidden.onHidden(() => {
      handleEntries(po.takeRecords() );
      po.disconnect();
    }, true);
  }
}
Calculates the [FID](https://web.dev/fid/) value for the current page and
calls the `callback` function once the value is ready, along with the
relevant `first-input` performance entry used to determine the value. The
reported value is a `DOMHighResTimeStamp`.

_**Important:** since FID is only reported after the user interacts with the
page, it's possible that it will not be reported for some page loads._