[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).


fiber = ((type: any): Fiber);
                fiber.pendingProps = pendingProps;
                fiber.expirationTime = expirationTime;
                return fiber;
              } else {
                throwOnInvalidElementType(type, owner);
              }
              break;
          }
        } else {
          throwOnInvalidElementType(type, owner);
        }
      }
    }
  }
  fiber = createFiber(fiberTag, pendingProps, key, mode);
  fiber.type = type;
  fiber.expirationTime = expirationTime;
  if (__DEV__) {
    fiber._debugSource = element._source;
    fiber._debugOwner = element._owner;
  }
  return fiber;
}
function throwOnInvalidElementType(type, owner) {