holder.js
function startVisibilityCheck() {
	    if (!App.vars.visibilityCheckStarted) {
	        global.requestAnimationFrame(visibilityCheck);
	        App.vars.visibilityCheckStarted = true;
	    }
	}
function startVisibilityCheck() {
	    if (!App.vars.visibilityCheckStarted) {
	        global.requestAnimationFrame(visibilityCheck);
	        App.vars.visibilityCheckStarted = true;
	    }
	}
function startVisibilityCheck ( ) { if ( ! App . vars . visibilityCheckStarted ) { global . requestAnimationFrame ( visibilityCheck ) ; App . vars . visibilityCheckStarted = true ; } }
Starts checking for invisible placeholders if not doing so yet. Does nothing otherwise.

@private
Starts checking for invisible placeholders if not doing so yet . Does nothing otherwise .