x11: Clicking on a SwitcherPopup without mouse grab causes UI to become unresponsive
This is a follow-up from the discussion of !2287 (merged). Alt+Tab can be opened without a mouse grab. So it is possible to open the switcher with the Chrome context menu open which only takes a mouse grab. Once opened after gnome-shell has acquired the keyboard grab, Chrome drops the mouse grab and closes the menu, allowing to interact with the switcher using the mouse. Clicking somewhere on the switcher in this state results in the UI pretty much becoming unresponsive.