[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).


nextFlushedRoot !== null &&
        nextFlushedExpirationTime !== NoWork &&
        (minExpirationTime === NoWork ||
          minExpirationTime >= nextFlushedExpirationTime) &&
        (!deadlineDidExpire ||
          recalculateCurrentTime() >= nextFlushedExpirationTime)
      ) {
        performWorkOnRoot(
          nextFlushedRoot,
          nextFlushedExpirationTime,
          !deadlineDidExpire,
        );
        findHighestPriorityRoot();
      }
    } else {
      while (
        nextFlushedRoot !== null &&
        nextFlushedExpirationTime !== NoWork &&
        (minExpirationTime === NoWork ||
          minExpirationTime >= nextFlushedExpirationTime)
      ) {
        performWorkOnRoot(nextFlushedRoot, nextFlushedExpirationTime, false);
        findHighestPriorityRoot();
      }
    }
    
    
    
    if (deadline !== null) {
      callbackExpirationTime = NoWork;