Whenever review or approval of the application by the County Planning Board is required by § 5 of P.L. 1968, c. 285 (N.J.S.A. 40:27-6.3), in the case of a subdivision, or § 8 of P.L. 1968, c. 285 (N.J.S.A. 40:27-6.6), in the case of a site plan, the Planning Board acting as a Board of Adjustment shall condition any approval that it grants upon timely receipt of a favorable report on the application by the County Planning Board or approval by the County Planning Board by its failure to report thereon within the required time.