Cleanup handling of XSynchronize
Don't have the context call into X11 code - instead have the various X11 connection handlers (MetaBackendX11 and MetaX11Display) just fetch a dumb "is synchronized" from the context.
Also remove some dead code.
Don't have the context call into X11 code - instead have the various X11 connection handlers (MetaBackendX11 and MetaX11Display) just fetch a dumb "is synchronized" from the context.
Also remove some dead code.