Remove Decoration of single window in Gnome 3
Solution 1:
You can try to use _MOTIF_WM_HINTS...
To remove decorations:xprop -f _MOTIF_WM_HINTS 32c -set _MOTIF_WM_HINTS "0x2, 0x0, 0x0, 0x0, 0x0"
To add decorations:xprop -f _MOTIF_WM_HINTS 32c -set _MOTIF_WM_HINTS "0x2, 0x0, 0x1, 0x0, 0x0"
xprop will then ask you to select window or if you know window id then you can also pass -id parameter to xprop. Only you can not use mouse to resize windows, but keybindings should work.