Looks like nobody ever asked this but this might be pretty useful for the pro user to figure out a good way to handle it.
I'm working with full screen windows all the time, to take full advantage of the gestures to easily navigate between tabs.
Sometimes I split my browser tabs by simply dragging one tab out, which then moves it to a new full screen window (see the following gif).
Now merging them back is quite a hassle,
is there any simple way to do it?