woothemes/woocommerce — pull request #5104 by InoPlugs (2014-03-11 18:49:03+00:00)
Title: Update class-wc-checkout.php

We need this hook to mark the fees our plugin (additional fee based on gateway) adds to the the order. Otherwise we can't tell if a fee was added by the user (Add fee button), by another plugin or by our plugin.