Added chromeos/dbus/OWNERS.

Added an OWNERS file to chromeos/dbus and set per-file owners for the Bluetooth
and NFC client code.

BUG=none
R=keybuk@chromium.org, satorux@chromium.org

Review URL: https://codereview.chromium.org/178143005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253338 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253338