DrupalFile7Migration::prepareRow override $argument['file_class']

Problem/Motivation

In order to leverage the MigrateFileUriAsIs class, the DrupalFileMigration class allows migrations to inject their own value to the file_class argument. However, DrupalFile7Migration::prepareRow() has an else condition that will apply $this->destination->setFileClass('MigrateFileUri'); to any file row that isn't a Youtube or oEmbed asset.

Proposed resolution

Remove that else condition to allow the migration argument setting to be the default behavior.

Remaining tasks

All the things.

User interface changes

None.

API changes

Restores function of the file_class argument.

Data model changes

None.