[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).


Ref,
  Incomplete,
  HostEffectMask,
  ErrLog,
} from 'shared/ReactTypeOfSideEffect';
import {
  HostRoot,
  ClassComponent,
  HostComponent,
  ContextProvider,
  HostPortal,
} from 'shared/ReactTypeOfWork';
import {
  enableUserTimingAPI,
  warnAboutDeprecatedLifecycles,
  replayFailedUnitOfWorkWithInvokeGuardedCallback,
} from 'shared/ReactFeatureFlags';
import getComponentName from 'shared/getComponentName';
import invariant from 'fbjs/lib/invariant';
import warning from 'fbjs/lib/warning';
import ReactFiberBeginWork from './ReactFiberBeginWork';
import ReactFiberCompleteWork from './ReactFiberCompleteWork';
import ReactFiberUnwindWork from './ReactFiberUnwindWork';
import ReactFiberCommitWork from './ReactFiberCommitWork';
import ReactFiberHostContext from './ReactFiberHostContext';
import ReactFiberHydrationContext from './ReactFiberHydrationContext';
import ReactFiberInstrumentation from './ReactFiberInstrumentation';
import ReactDebugCurrentFiber from './ReactDebugCurrentFiber';
import {
  recordEffect,