Issue #2837676 by michielnugter, droplet, alexpott, Lendude, jibran, klausi,...

Issue #2837676 by michielnugter, droplet, alexpott, Lendude, jibran, klausi, Wim Leers: Provide a better way to validate all javascript activity is completed

(cherry picked from commit 3af641f1)