This is a potential leak discovered by static analysis, in fact if _COGL_GET_CONTEXT returns, the newly allocated struct isn't released. https://gitlab.gnome.org/GNOME/mutter/merge_requests/1195
In cogl use cogl-config.h and in clutter use clutter-build-config.h. We can't use clutter-config.h in clutter because its already used and installed. https://bugzilla.gnome.org/show_bug.cgi?id=768976
