[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).


currentTime,
          committedExpirationTime,
        );
      }
      if (effectTag & ErrLog) {
        commitErrorLogging(nextEffect, onUncaughtError);
      }
      if (effectTag & Ref) {
        recordEffect();
        commitAttachRef(nextEffect);
      }
      const next = nextEffect.nextEffect;
      // Ensure that we clean these up so that we don't accidentally keep them.
      // I'm not actually sure this matters because we can't reset firstEffect
      // and lastEffect since they're on every node, not just the effectful
      // ones. So we have to clean everything as we reuse nodes anyway.
      nextEffect.nextEffect = null;
      // Ensure that we reset the effectTag here so that we can rely on effect
      // tags to reason about the current life-cycle.
      nextEffect = next;
    }
  }
  function isAlreadyFailedLegacyErrorBoundary(instance: mixed): boolean {
    return (
      legacyErrorBoundariesThatAlreadyFailed !== null &&
      legacyErrorBoundariesThatAlreadyFailed.has(instance)
    );
  }
  function markLegacyErrorBoundaryAsFailed(instance: mixed) {
    if (legacyErrorBoundariesThatAlreadyFailed === null) {