There’s been no official announcement (to the best of FedLine’s knowledge, anyway), but the federal government now has a new top performance official, at least temporarily. “Acting chief performance officer” was the title that Lisa Brown used in a Friday post on the Office of Management and Budget’s official blog. Brown, whose Obama administration assignments have hitherto included assistant to the president and staff secretary, helped assemble the White House’s blueprint for reorganization of federal trade and export agencies. Until recently, the federal chief performance officer was Jeff Zients, who also served as OMB’s deputy director for management. But Zients…