Add a sparse histogram to record the checksum of the reset program executed.

BUG=298036

Review URL: https://codereview.chromium.org/155613005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251658 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251658