Berkshire Hathaway on Monday announced a slew of executive shakeups ahead of Warren Buffett’s departure this year, including Geico CEO Todd Combs, who is heading to JPMorgan Chase.Combs, 54, will lead JPMorgan’s new Security and Resiliency Initiative, where he will have $10 billion to start launching investments in defense, aerospace, health care and energy.The hedge fund manager came to Berkshire in 2010 to help manage the conglomerate’s portfolio of investments. He liquidated his hedge fund, Castle Point, ...