We now can import standalone ONC files that are encrypted by the
Spigots management app.
TBR=joaodasilva@chromium.org
BUG=chromium-os:19397
TEST=Ran new unit tests, imported encrypted ONC on device.
Review URL: http://codereview.chromium.org/8949056
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@117321 0039d316-1c4b-4281-b951-d872f2087c98