While working on the DevTools profiler, I've noticed that durations are sometimes incorrect. This seems to be vaguely related to high/low priority state updates. Need to track this down more so I'm filing an issue for myself.
/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */
import type {ReactProviderType, ReactContext} from 'shared/ReactTypes';
import type {Fiber} from 'react-reconciler/src/ReactFiber';
import type {FiberRoot} from './ReactFiberRoot';
import type {ExpirationTime} from './ReactFiberExpirationTime';
import checkPropTypes from 'prop-types/checkPropTypes';
import {
  IndeterminateComponent,
  FunctionalComponent,
  ClassComponent,
  HostRoot,
  HostComponent,
  HostText,
  HostPortal,
  ForwardRef,
  Fragment,
  Mode,
  ContextProvider,
  ContextConsumer,
  Profiler,
  PlaceholderComponent,
} from 'shared/ReactTypeOfWork';