GitLab

This is a split of https://codereview.chromium.org/284443002/, to avoid
merging issues.

It is almost impossible to land a CL adding histograms via CQ, without
a merging conflict.

TBR=isherman@chromium.org
TEST=Just histograms, no actual changes.
BUG=248427

Review URL: https://codereview.chromium.org/288483002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@269968 0039d316-1c4b-4281-b951-d872f2087c98