Changed NS_ASSERTION to NS_ENSURE on an interface boundary check. Done mainly to get VC depend to rebuild this file so tinderbox will go green.

webshell/tests/viewer/nsWinMain.cpp

@@ -108,7 +108,7 @@ nsNativeBrowserWindow::CreateMenuBar(PRInt32 aWidth)
 nsresult
 nsNativeBrowserWindow::GetMenuBarHeight(PRInt32 * aHeightOut)
 {
-  NS_ASSERTION(nsnull != aHeightOut,"null out param.");
+  NS_ENSURE_ARG_POINTER(aHeightOut);
 
   *aHeightOut = 0;