Mark usbPrivate API's histogram enums as DELETED_

usbPrivate was already deleted in https://codereview.chromium.org/617933002,
so mark their corresponding historgram enum as deleted.

Bug: None
Change-Id: I83776a8c5e1977f4262a12e7dbdc03d2f1140684
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1752178
Commit-Queue: Istiaque Ahmed <lazyboy@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686804}
2 files changed