Widget: Define this.document properly when instantiating a widget on a document or window. Fixes #7835 - Undefined property when creating widgets.

Author: scottgonzalez

ui/jquery.ui.widget.js

@@ -195,7 +195,11 @@ $.Widget.prototype = {
 		if ( element !== this ) {
 			$.data( element, this.widgetName, this );
 			this._bind({ remove: "destroy" });
-			this.document = $( element.ownerDocument );
+			this.document = $( element.style ?
+				// element within the document
+				element.ownerDocument :
+				// element is window or document
+				element.document || element );
 			this.window = $( this.document[0].defaultView || this.document[0].parentWindow );
 		}