Twitter has named Canadian Patrick Pichette chairman of the company. Pichette was previously an independent director of the social media company, which is headed by CEO Jack Dorsey. The executive chairman of Twitter, Omid Kordestani, resigns that position but remains an independent board member. Pichette, former Google financial chief, says this is the right time to improve Twitter’s governance structure with shifts at the top. There was a lot to do earlier about the way in which the company was run. In March, activist investor Elliott Management criticized the policies of Twitter and CEO Dorsey. The investment fund is said to have initially driven Dorsey’s departure after buying in with a significant stake. Ultimately, the parties reached an agreement whereby Elliot partner Jesse Cohn joined the board of Twitter.