Convert //ash from scoped_ptr to std::unique_ptr

ash/wm/lock_state_controller.cc

Index: ash/wm/lock_state_controller.cc
diff --git a/ash/wm/lock_state_controller.cc b/ash/wm/lock_state_controller.cc
index b381ee8d3a0d419413bd9e81bb7ad8ede9e37695..247404d1efb6796fe7d9b550f89ee045de25b1ae 100644
--- a/ash/wm/lock_state_controller.cc
+++ b/ash/wm/lock_state_controller.cc
@@ -103,7 +103,7 @@ LockStateController::~LockStateController() {
 }
 
 void LockStateController::SetDelegate(
-    scoped_ptr<LockStateControllerDelegate> delegate) {
+    std::unique_ptr<LockStateControllerDelegate> delegate) {
   delegate_ = std::move(delegate);
 }