commit d13efc631465937542ea5e590a5c1590a5bfb253
Author: LIU Yulong <i@liuyulong.me>
Date:   Wed Jun 17 23:06:38 2020 +0800

    [L3] Let agent extension do delete router first
    
    For some agent extension implementation, it may need the router_info
    to do some clean up work. So this patch just moves the extension
    delete action forward.
    
    Closes-Bug: #1897423
    Change-Id: I3434ec7c0942229b99e67de7500090dedb37b13f

diff --git a/neutron/agent/l3/agent.py b/neutron/agent/l3/agent.py
index 7ffb025..87da3cf 100644
--- a/neutron/agent/l3/agent.py
+++ b/neutron/agent/l3/agent.py
@@ -511,9 +511,9 @@ class L3NATAgent(ha.AgentMixin,
         ri = self.router_info.get(router_id)
 
         try:
-            self._router_removed(ri, router_id)
             if ri:
                 self.l3_ext_manager.delete_router(self.context, ri.router)
+            self._router_removed(ri, router_id)
         except Exception:
             LOG.exception('Error while deleting router %s', router_id)
             return False