Fix error logging for EndConnection.

blimp/client/session/blimp_client_session.cc

Index: blimp/client/session/blimp_client_session.cc
diff --git a/blimp/client/session/blimp_client_session.cc b/blimp/client/session/blimp_client_session.cc
index 5b75a823bcd20db99095917cf5d495c902af898c..4fc9834f29bc3e5aedc7ffa8fd5983adde1e4989 100644
--- a/blimp/client/session/blimp_client_session.cc
+++ b/blimp/client/session/blimp_client_session.cc
@@ -161,7 +161,11 @@ void ClientNetworkComponents::HandleConnection(
 }
 
 void ClientNetworkComponents::OnConnectionError(int result) {
-  VLOG(1) << "Connection error: " << net::ErrorToString(result);
+  if (result >= 0) {
+    VLOG(1) << "Disconnected with reason: " << result;
+  } else {
+    VLOG(1) << "Connection error: " << net::ErrorToString(result);
+  }
   network_observer_->OnDisconnected(result);
 }