The histogram is not used anymore. Remove to safe resources.

Bug: chromium:926072
Change-Id: I929f34f7ab0613431eaf9740f3342b6b2cec6cbd
Reviewed-on: https://chromium-review.googlesource.com/c/1477672Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59684}