[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).


case PlacementAndUpdate: {
          
          commitPlacement(nextEffect);
          
          
          nextEffect.effectTag &= ~Placement;
          
          const current = nextEffect.alternate;
          commitWork(current, nextEffect);
          break;
        }
        case Update: {
          const current = nextEffect.alternate;
          commitWork(current, nextEffect);
          break;
        }
        case Deletion: {
          commitDeletion(nextEffect);
          break;
        }
      }
      nextEffect = nextEffect.nextEffect;
    }
    if (__DEV__) {
      ReactDebugCurrentFiber.resetCurrentFiber();
    }
  }
  function commitBeforeMutationLifecycles() {
    while (nextEffect !== null) {
      const effectTag = nextEffect.effectTag;