Calling `ReactDefaultPerf.printWasted()` results in:

```
Uncaught TypeError: Cannot read property 'forEach' of undefined
writes.(anonymous function).forEach @ ReactDefaultPerfAnalysis.js:195
Object.keys.forEach @ ReactDefaultPerfAnalysis.js:192
getUnchangedComponents @ ReactDefaultPerfAnalysis.js:191
getInclusiveSummary @ ReactDefaultPerfAnalysis.js:139
ReactDefaultPerf.getMeasurementsSummaryMap @ ReactDefaultPerf.js:118
ReactDefaultPerf.printWasted @ ReactDefaultPerf.js:133
```

(this is on a page internally at Facebook so I assume it's a fairly recent React version)

var items = [];
  measurements.forEach(function(measurement) {
    Object.keys(measurement.writes).forEach(function(id) {
      measurement.writes[id].forEach(function(write) {
        items.push({
          id: id,
          type: DOM_OPERATION_TYPES[write.type] || write.type,
          args: write.args,
        });
      });
    });
  });
  return items;
}
function getExclusiveSummary(measurements) {
  var candidates = {};
  var displayName;
  for (var i = 0; i < measurements.length; i++) {
    var measurement = measurements[i];
    var allIDs = Object.assign(
      {},
      measurement.exclusive,
      measurement.inclusive
    );
    for (var id in allIDs) {
      displayName = measurement.displayNames[id].current;
      candidates[displayName] = candidates[displayName] || {
        componentName: displayName,
        inclusive: 0,
        exclusive: 0,