Removal of OrderedDescriptor has broken SkyOffsetFrame when using SkyCoord #11254

>>> import astropy.units as u
>>> from astropy.coordinates import SkyCoord, SkyOffsetFrame, ICRS

>>> origin = SkyCoord(10*u.deg, 0*u.deg, frame='icrs')
>>> offset_frame = SkyOffsetFrame(origin=origin)
>>> coord = SkyCoord(3*u.deg, 4*u.deg, frame=offset_frame)
>>> coord
<SkyCoord (SkyOffsetICRS: rotation=0.0 deg, origin=<ICRS Coordinate: (ra, dec) in deg
    (10., 0.)>): (lon, lat) in deg
    (3., 4.)>

>>> coord.transform_to('icrs')
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-21-d349054966e0> in <module>
----> 1 coord.transform_to('icrs')

c:\users\ayshih\onedrive\code\astropy\astropy\coordinates\sky_coordinate.py in transform_to(self, frame, merge_attributes)
    625             frame_kwargs.pop(attr)
    626 
--> 627         return self.__class__(new_coord, **frame_kwargs)
    628 
    629     def apply_space_motion(self, new_obstime=None, dt=None):

c:\users\ayshih\onedrive\code\astropy\astropy\coordinates\sky_coordinate.py in __init__(self, copy, *args, **kwargs)
    321             for attr in skycoord_kwargs:
    322                 # Setting it will also validate it.
--> 323                 setattr(self, attr, skycoord_kwargs[attr])
    324 
    325             if info is not None:

c:\users\ayshih\onedrive\code\astropy\astropy\coordinates\sky_coordinate.py in __setattr__(self, attr, val)
    809             super().__setattr__('_' + attr, val)
    810             # Validate it
--> 811             frame_transform_graph.frame_attributes[attr].__get__(self)
    812             # And add to set of extra attributes
    813             self._extra_frameattr_names |= {attr}

c:\users\ayshih\onedrive\code\astropy\astropy\coordinates\attributes.py in __get__(self, instance, frame_cls)
    102                 out = getattr(instance, self.secondary_attribute, self.default)
    103 
--> 104         out, converted = self.convert_input(out)
    105         if instance is not None:
    106             instance_shape = getattr(instance, 'shape', None)  # None if instance (frame) has no data!

c:\users\ayshih\onedrive\code\astropy\astropy\coordinates\attributes.py in convert_input(self, value)
    445         if value is None:
    446             return None, False
--> 447         elif isinstance(value, self._frame):
    448             return value, False
    449         else:

TypeError: isinstance() arg 2 must be a type or tuple of types

>>> coord.frame.transform_to(ICRS())
<ICRS Coordinate: (ra, dec) in deg
    (13., 4.)>

>>> offset_frame.frame_attributes['origin']._frame is None
True