[This example](https://codesandbox.io/s/1zn2o513pq) presents a huge performance drop between React 16.2 and React 16.3.

In investigated it and noticed several things:

- Perfomance drop is only visible using development bundle
- This is not related to styled-components (a simple div presents the same problem)
- I tried to investigate in performance tab of Chrome dev tools and I noticed that I get React measures even without "?react_perf"
- React Tree Reconciliation seems very long, do not know why

It is not a big problem for me, but it looks weird, so I decided to [share it on Twitter](https://twitter.com/neoziro/status/979756579296817154),  then @gaearon [invited me to submit an issue about it](https://twitter.com/dan_abramov/status/980036013518139398).


callbackID = -1;
    }
    
    if (nextFlushedExpirationTime !== NoWork) {
      scheduleCallbackWithExpiration(nextFlushedExpirationTime);
    }
    
    deadline = null;
    deadlineDidExpire = false;
    finishRendering();
  }
  function flushRoot(root: FiberRoot, expirationTime: ExpirationTime) {
    invariant(
      !isRendering,
      'work.commit(): Cannot commit while already rendering. This likely ' +
        'means you attempted to commit from inside a lifecycle method.',
    );
    
    
    
    nextFlushedRoot = root;
    nextFlushedExpirationTime = expirationTime;
    performWorkOnRoot(root, expirationTime, false);
    
    performSyncWork();
    finishRendering();
  }
  function finishRendering() {
    nestedUpdateCount = 0;
    if (completedBatches !== null) {