[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 = scheduleDeferredCallback(performAsyncWork, {timeout});
  }
  
  
  function requestWork(root: FiberRoot, expirationTime: ExpirationTime) {
    addRootToSchedule(root, expirationTime);
    if (isRendering) {
      
      
      return;
    }
    if (isBatchingUpdates) {
      
      if (isUnbatchingUpdates) {
        
        
        nextFlushedRoot = root;
        nextFlushedExpirationTime = Sync;
        performWorkOnRoot(root, Sync, false);
      }
      return;
    }
    
    if (expirationTime === Sync) {
      performSyncWork();
    } else {
      scheduleCallbackWithExpiration(expirationTime);
    }
  }
  function addRootToSchedule(root: FiberRoot, expirationTime: ExpirationTime) {