Suppress network configuration UI when third-party VPN times out

BUG=470835

Review URL: https://codereview.chromium.org/1034923002

Cr-Commit-Position: refs/heads/master@{#322397}

ui/chromeos/network/network_connect.cc

@@ -142,12 +142,18 @@ void NetworkConnectImpl::HandleUnconfiguredNetwork(
     return;
   }
 
-  if (network->type() == shill::kTypeWimax ||
-      network->type() == shill::kTypeVPN) {
+  if (network->type() == shill::kTypeWimax) {
     delegate_->ShowNetworkConfigure(service_path);
     return;
   }
 
+  if (network->type() == shill::kTypeVPN) {
+    // Third-party VPNs handle configuration UI themselves.
+    if (network->vpn_provider_type() != shill::kProviderThirdPartyVpn)
+      delegate_->ShowNetworkConfigure(service_path);
+    return;
+  }
+
   if (network->type() == shill::kTypeCellular) {
     if (network->RequiresActivation()) {
       ActivateCellular(service_path);