Was there a ContributionType.php file in a earlier version
To answer your exact question - in CiviCRM 4.3+ ContributionType became FinancialType.  You might be able to just change the file name.

That said, Xavier is correct - there's likely a newer version of the payment processor.  You might want to ask J.C. Grogan.  Xavier is also correct that in Civi 4.4+ this code is probably supplanted because of pseudoconstant lookups.