GitLab

I removed these histograms in March 2017 in
https://codereview.chromium.org/2764683002 but I forgot to mark them as
obsolete in histograms.xml.

Mark them as obsolete.

BUG=700568

Change-Id: I76e83d25ea45488ae8631c6402171dda3e61f987
Reviewed-on: https://chromium-review.googlesource.com/1161719Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580820}