[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).


let result = computeAsyncExpiration(currentTime);
    if (result <= lastUniqueAsyncExpiration) {
      
      
      
      result = lastUniqueAsyncExpiration + 1;
    }
    lastUniqueAsyncExpiration = result;
    return lastUniqueAsyncExpiration;
  }
  function computeExpirationForFiber(fiber: Fiber) {
    let expirationTime;
    if (expirationContext !== NoWork) {
      
      expirationTime = expirationContext;
    } else if (isWorking) {
      if (isCommitting) {
        
        
        expirationTime = Sync;
      } else {
        
        
        expirationTime = nextRenderExpirationTime;
      }
    } else {
      
      
      if (fiber.mode & AsyncMode) {
        if (isBatchingInteractiveUpdates) {