Version 15.4.1

As starting Chrome 55, there is a new event `auxclick` to handle middle click, and `click` doesn't trigger by middle click anymore
https://developers.google.com/web/updates/2016/10/auxclick
export const TOP_DRAG = unsafeCastStringToDOMTopLevelType('drag');
export const TOP_DRAG_END = unsafeCastStringToDOMTopLevelType('dragend');
export const TOP_DRAG_ENTER = unsafeCastStringToDOMTopLevelType('dragenter');
export const TOP_DRAG_EXIT = unsafeCastStringToDOMTopLevelType('dragexit');
export const TOP_DRAG_LEAVE = unsafeCastStringToDOMTopLevelType('dragleave');
export const TOP_DRAG_OVER = unsafeCastStringToDOMTopLevelType('dragover');
export const TOP_DRAG_START = unsafeCastStringToDOMTopLevelType('dragstart');
export const TOP_DROP = unsafeCastStringToDOMTopLevelType('drop');
export const TOP_DURATION_CHANGE = unsafeCastStringToDOMTopLevelType(
  'durationchange',
);
export const TOP_EMPTIED = unsafeCastStringToDOMTopLevelType('emptied');
export const TOP_ENCRYPTED = unsafeCastStringToDOMTopLevelType('encrypted');
export const TOP_ENDED = unsafeCastStringToDOMTopLevelType('ended');
export const TOP_ERROR = unsafeCastStringToDOMTopLevelType('error');
export const TOP_FOCUS = unsafeCastStringToDOMTopLevelType('focus');
export const TOP_GOT_POINTER_CAPTURE = unsafeCastStringToDOMTopLevelType(
  'gotpointercapture',
);
export const TOP_INPUT = unsafeCastStringToDOMTopLevelType('input');
export const TOP_INVALID = unsafeCastStringToDOMTopLevelType('invalid');
export const TOP_KEY_DOWN = unsafeCastStringToDOMTopLevelType('keydown');
export const TOP_KEY_PRESS = unsafeCastStringToDOMTopLevelType('keypress');
export const TOP_KEY_UP = unsafeCastStringToDOMTopLevelType('keyup');
export const TOP_LOAD = unsafeCastStringToDOMTopLevelType('load');
export const TOP_LOAD_START = unsafeCastStringToDOMTopLevelType('loadstart');
export const TOP_LOADED_DATA = unsafeCastStringToDOMTopLevelType('loadeddata');
export const TOP_LOADED_METADATA = unsafeCastStringToDOMTopLevelType(
  'loadedmetadata',
);