We have a few stale comments about getEventModifierState:

https://github.com/facebook/react/blob/663835a43a5a92ff63c3e3b43e4c9ff40dde173b/packages/react-dom/src/events/getEventModifierState.js#L24-L26

IE8 isn't an issue anymore, [but Safari probably still is](https://caniuse.com/#feat=keyboardevent-getmodifierstate). It'd be nice to figure out specifically why we still need this module and update the comment with that info.


const syntheticEvent = this;
  const nativeEvent = syntheticEvent.nativeEvent;
  if (nativeEvent.getModifierState) {
    return nativeEvent.getModifierState(keyArg);
  }
  const keyProp = modifierKeyToProp[keyArg];
  return keyProp ? !!nativeEvent[keyProp] : false;
}
function getEventModifierState(
  nativeEvent: AnyNativeEvent,
): (keyArg: string) => boolean {
  return modifierStateGetter;
}
export default getEventModifierState;