[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).


this.updateQueue = null;
  this.memoizedState = null;
  this.mode = mode;
  
  this.effectTag = NoEffect;
  this.nextEffect = null;
  this.firstEffect = null;
  this.lastEffect = null;
  this.expirationTime = NoWork;
  this.alternate = null;
  if (__DEV__) {
    this._debugID = debugCounter++;
    this._debugSource = null;
    this._debugOwner = null;
    this._debugIsCurrentlyTiming = false;
    if (!hasBadMapPolyfill && typeof Object.preventExtensions === 'function') {
      Object.preventExtensions(this);
    }
  }
}
const createFiber = function(
  tag: TypeOfWork,
  pendingProps: mixed,
  key: null | string,
  mode: TypeOfMode,
): Fiber {
  
  return new FiberNode(tag, pendingProps, key, mode);
};
function shouldConstruct(Component) {