Summary: We already have this information for all VCSes, there's no point in parsing it again. We currently support it only for Git and I remember there were some bugs in it. It should also be faster. Test Plan: Blamed previous revision of a file which was moved in SVN. Reviewers: epriestley Reviewed By: epriestley CC: aran, Korvin Differential Revision: https://secure.phabricator.com/D3564