
This patch removes the X11 specific code from MetaBarrier and creates an abstraction layer MetaBarrierImpl. The existing X11 implementation is moved to a new GObject MetaBarrierImplX11 implementing the abstract interface MetaBarrierImpl which is instantiated by MetaBarrier when supported. While at it, move it to backends/ and properly name the files. https://bugzilla.gnome.org/show_bug.cgi?id=706655