Add histograms for DHCP option failures

Add per-network-technology histograms that will be emitted by
shill whenever it encounters a broken DHCP installation.

BUG=297607
TEST=Start chrome, and browse to chrome://histograms to make sure
these enums now exist.

Review URL: https://codereview.chromium.org/46663007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236255 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236255