function getCompositionEventType(topLevelType) {
	  switch (topLevelType) {
	    case 'topCompositionStart':
	      return eventTypes.compositionStart;
	    case 'topCompositionEnd':
	      return eventTypes.compositionEnd;
	    case 'topCompositionUpdate':
	      return eventTypes.compositionUpdate;
	  }
	}
Translate native top level events into event types.

@param {string} topLevelType
@return {object}