Update histograms.xml to match UseCounter.h.

BUG=348003

Review URL: https://codereview.chromium.org/189093007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255674 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255674