Unit-ify the compute API resize tests

Move resize related compute API tests to test_compute_api and make them
unit tests.  This makes test changes easier when converting to objects.

This also caught a couple things where the cells compute api class was
not in sync that don't really end up being bugs, but need to match for
tests to pass.

Change-Id: I194310beb5e821e4a8262310d1bb80e0747e1c43