Bruce Flatt put Wall Street’s biggest private equity players on notice that the Canadian juggernaut was coming for them three years ago. The head of Brookfield Asset Management Inc. told Bloomberg Television then that his firm -- pushing into private equity -- should be mentioned in the same breath as Blackstone Group LP, Carlyle Group LP and KKR & Co. It was an unusually brash statement from the understated Winnipeg native. On Wednesday, Brookfield Asset Management agreed to buy a majority stake in Oaktree Capital, a move that will create a $475 billion alternative-investing behemoth.