Fix #14150: revert to ownerDocument.defaultView.getComputedStyle. Close...

Fix #14150: revert to ownerDocument.defaultView.getComputedStyle. Close gh-1311. (cherry-picked from 3e3680c2)

src/css.js

@@ -291,7 +291,7 @@ jQuery.extend({
 // because jsdom on node.js will break without it.
 if ( window.getComputedStyle ) {
 	getStyles = function( elem ) {
-		return window.getComputedStyle( elem, null );
+		return elem.ownerDocument.defaultView.getComputedStyle( elem, null );
 	};
 
 	curCSS = function( elem, name, _computed ) {