I've tested the new Perf tools on one of the screens in one app I'm working on and it works great :)

One thing I wanted also on the old one Perf tools was to be able to check whether the Perf tools are started or stopped, so basically exposing `ReactDebugTool`'s `isProfiling` variable. My use for that is that I have a keyboard shortcut (in development) bound to start/stop the Perf tools and currently I'm forced to maintain such a variable myself to know whether to start or stop (which gets out of sync if I start/stop the perf tools without the keyboard shortcut).

If you don't think it's worthwhile to expose `isProfiling` feel free to close this issue.

var stats = getWasted(flushHistory);
  var table = stats.map(item => {
    var {key, instanceCount, inclusiveRenderDuration, renderCount} = item;
    return {
      'Owner > Component': key,
      'Inclusive wasted time (ms)': roundFloat(inclusiveRenderDuration),
      'Instance count': instanceCount,
      'Render count': renderCount,
    };
  });
  console.table(table);
}
function printOperations(flushHistory) {
  var stats = getOperations(flushHistory);
  var table = stats.map(stat => ({
    'Owner > Node': stat.key,
    'Operation': stat.type,
    'Payload': typeof stat.payload === 'object' ?
      JSON.stringify(stat.payload) :
      stat.payload,
    'Flush index': stat.flushIndex,
    'Owner Component ID': stat.ownerID,
    'DOM Component ID': stat.instanceID,
  }));
  console.table(table);
}
var warnedAboutPrintDOM = false;
function printDOM(measurements) {