Disabled part of the test that can never pass.
Disabled part of the test that can never pass.

Xdmf always reads polydata as unstructured grid. The memory  usage
of unstructured is always different than polydata so the two should
not be compared. Disabled.

cjh1/Xdmf2,cjh1/Xdmf2,cjh1/Xdmf2