Set the "namespace" of the surface.
No one is quite sure what this is for, but it probably should be something generic ("panel", "osk", etc). The name_space
string is copied, and caller maintains ownership of original. If the window is currently mapped, it will get remapped so the change can
take effect.
Default is "gtk-layer-shell" (which will be used if set to null)
| window |
A layer surface. |
| name_space |
The namespace of this layer surface. |