Delay the result of the readyState check to give scripts the opportunity to delay ready, as described by @jrburke in 747ba7defd.

src/core.js

@@ -429,7 +429,8 @@ jQuery.extend({
 		// Catch cases where $(document).ready() is called after the
 		// browser event has already occurred.
 		if ( document.readyState === "complete" ) {
-			return jQuery.ready();
+			// Handle it asynchronously to allow scripts the opportunity to delay ready
+			return setTimeout( jQuery.ready, 13 );
 		}
 
 		// Mozilla, Opera and webkit nightlies currently support this event