Comment 9 for bug 1413817

Reviewed: https://review.openstack.org/174268
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=5f28762ae2a96b8062628d0cac81f5da94c6ed34
Submitter: Jenkins
Branch: master

commit 5f28762ae2a96b8062628d0cac81f5da94c6ed34
Author: John Schwarz <email address hidden>
Date: Thu Apr 16 12:01:26 2015 +0300

    Add callback prior to deleting a subnet

    When using LBaaS and trying to delete a subnet, neutron has no way of
    knowing if the subnet is associated to some pool. As a result, the
    subnet is deleted but the pool remains associated to the (now
    nonexistent) subnet_id. This patch lays the ground-work for adding a
    check in LBaaS' side to prevent such cases.

    Related-Bug: #1413817
    Change-Id: I3d5e231b67c72ffd919c92d65b57da56c63e053c