Out-of-band transforms are considered to be all actor transforms done
directly with the Cogl API instead of via ClutterActor::apply_transform.
By running with CLUTTER_DEBUG=oob-transform then Clutter will explicitly
try to detect when un-expected transforms have been applied to the
modelview matrix stack.
Out-of-band transforms can lead to awkward bugs in Clutter applications
because Clutter itself doesn't know about them and this can disrupt
Clutter's input handling and calculations of actor paint-volumes
which can lead to visual artifacts.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
