pgtk: dframe-reposition-frame doesn't work

[Yasushi SHOJI]

Hi Yuuki and others,

Thank you for working on PGTK. It's great to see emacs working on
Wayland without X.

Today I noticed that the speedbar frame doesn't attach to the main frame
when I `(speedbar-get-focus)`.  Does anyone see this behaviour?

An ECM I came up with is this:

,----
| (let ((f (make-frame))
|       (c (window-frame (get-buffer-window (current-buffer)))))
|   (require 'dframe)
|   (dframe-reposition-frame f c 'left))
`----
-- 
               yashi