Adds Window::MoveChildToFront, with surrounding changes.

chrome/browser/chromeos/native_dialog_window.cc

Index: chrome/browser/chromeos/native_dialog_window.cc
diff --git a/chrome/browser/chromeos/native_dialog_window.cc b/chrome/browser/chromeos/native_dialog_window.cc
index b6ca24bef3d0870e66268e0720714a743b77a60e..dd974c51a7d59d52a6ba065ac0feb4ea19d161c7 100644
--- a/chrome/browser/chromeos/native_dialog_window.cc
+++ b/chrome/browser/chromeos/native_dialog_window.cc
@@ -153,7 +153,7 @@ void NativeDialogHost::OnCheckResize(GtkWidget* widget) {
       gfx::Rect window_bounds = GetWidget()->GetWindowScreenBounds();
       window_bounds.set_width(window_size.width());
       window_bounds.set_height(window_size.height());
-      GetWidget()->SetBoundsConstrained(window_bounds, NULL);
+      GetWidget()->SetBoundsConstrained(window_bounds);
     }
   }
 }