Though I'm actually confused as to why that `visitAll()`-`_clearCachedData()` loop is even needed -- non-watched entries are never supposed to cache anything to begin with, and unwatching clears the cache of anything that was previously watched (as we can see here).  Maybe that code is a remnant from before one of those things was true?

@iwehrman, can you remember why we do that in `_handleDirectoryChange()`?