Use winUtils.get() to get window from document. Refs #15216 !strict.

Dialog.js

@@ -16,7 +16,7 @@ define([
 	"dojo/on",
 	"dojo/ready",
 	"dojo/sniff", // has("ie") has("opera") has("dijit-legacy-requires")
-	"dojo/window", // winUtils.getBox
+	"dojo/window", // winUtils.getBox, winUtils.get
 	"dojo/dnd/Moveable", // Moveable
 	"dojo/dnd/TimedMoveable", // TimedMoveable
 	"./focus",
@@ -382,7 +382,7 @@ define([
 			}
 
 			// Recenter Dialog if user scrolls browser.  Connecting to document doesn't work on IE, need to use window.
-			var win = this.ownerDocument.defaultView || this.ownerDocument.parentWindow;
+			var win = winUtils.get(this.ownerDocument);
 			this._modalconnects.push(on(win, "scroll", lang.hitch(this, "resize")));
 
 			this._modalconnects.push(on(this.domNode, connect._keypress, lang.hitch(this, "_onKey")));

focus.js

@@ -376,7 +376,7 @@ define([
 
 	// register top window and all the iframes it contains
 	ready(function(){
-		var handle = singleton.registerWin(win.doc.parentWindow || win.doc.defaultView);
+		var handle = singleton.registerWin(winUtils.get(win.doc));
 		if(has("ie")){
 			unload.addOnWindowUnload(function(){
 				if(handle){	// because this gets called twice when doh.robot is running