SessionStorage: Remove expired histograms backed by leveldb::Status

These expired histograms rely on leveldb::Status. We are in the process
of adding an implementation agnostic Status for DOMStorage. Once that
lands, we'll add back any histograms we need using that new Status.

Bug: 377242771
Change-Id: I4e289d2804eb2596c5ea860b8a46bfaa1bca9d56
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6644020
Auto-Submit: Rahul Singh <rahsin@microsoft.com>
Reviewed-by: Evan Stade <evanstade@microsoft.com>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Reviewed-by: Ayu Ishii <ayui@chromium.org>
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1474955}