Go ahead and give him an Oscar already. After all, Johnny Depp’s best performance is also probably his last. Taking the stand Tuesday, Depp’s hourslong testimony, delivered in a soft, often halting voice, sounded nothing like a strident defense against spousal abuse. Instead, Depp depicted himself — brilliantly — as a confused, sad, gentle soul who somehow stumbled into global fame and ungodly wealth. As if the .000000001% of people who attain worldwide recognition and fortunes of more than $600 million get there by accident. At one point, Depp even stood up in the witness box to reenact his mother’s suicide attempt. Can you imagine? Selling out a parent’s lowest moment for public sympathy? This isn’t just the diminution of Johnny Depp. We’re watching the Death of the Movie Star.