Comment 2 for bug 1461221

@marmuta thank you for the info. It appears to be gtk3 client side decoration handicap. I can live with it.
I met another decoration problem, when I enable "show window decoration" and set transparency to 80 while inactive, then when I move mouse pointer on window decoration which has minimize, maximize and exit buttons, it loses focus and sets transparency, I can not see onboard while moving it in the screen. It's like window geometry is not covering onboard's window decoration.