Allow HTTP urls when device policy doesn't specify. BUG=chromium:277835 TEST=Unittest Change-Id: I638248dcbdbdaf48e38b79638b2348aa6c1400fb Previous-Reviewed-on: https://gerrit.chromium.org/gerrit/66732 (cherry picked from commit f7d8004834f54aaf642da6488521511e6b637fdc) Reviewed-on: https://chromium-review.googlesource.com/167712 Reviewed-by: Chris Sosa <sosa@chromium.org> Tested-by: Chris Sosa <sosa@chromium.org>