Missing operator= return values in StatusOr (#3014)
Missing operator= return values in StatusOr (#3014)

* Missing operator= return values in StatusOr
kythe/kythe,kythe/kythe,bzz/kythe,bzz/kythe,kythe/kythe,kythe/kythe,bzz/kythe,kythe/kythe,bzz/kythe,kythe/kythe,kythe/kythe,bzz/kythe,kythe/kythe,bzz/kythe,bzz/kythe,bzz/kythe,bzz/kythe,bzz/kythe,kythe/kythe,kythe/kythe,bzz/kythe,bzz/kythe,kythe/kythe