Silence a (spurious) use after free message

BUG=none
TEST=AsyncHostResolver.*


Review URL: http://codereview.chromium.org/8918029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114186 0039d316-1c4b-4281-b951-d872f2087c98

net/dns/async_host_resolver.cc

@@ -397,8 +397,8 @@ void AsyncHostResolver::OnDnsRequestComplete(
   requestlist_map_.erase(rit);
 
   // Cleanup |dns_req| and start a new one if there are pending requests.
-  delete dns_req;
   dns_requests_.remove(dns_req);
+  delete dns_req;
   ProcessPending();
 }