Add ability to bind a different InterfaceRegistry/InterfaceProvider to an incoming Connection.

services/shell/public/cpp/lib/connector_impl.cc

Index: services/shell/public/cpp/lib/connector_impl.cc
diff --git a/services/shell/public/cpp/lib/connector_impl.cc b/services/shell/public/cpp/lib/connector_impl.cc
index 1bd9e68924ceae8ffc2601469b9afb26974e2ee9..3d757d9b148187b0792f25ab703233e50fe3001e 100644
--- a/services/shell/public/cpp/lib/connector_impl.cc
+++ b/services/shell/public/cpp/lib/connector_impl.cc
@@ -60,8 +60,25 @@ std::unique_ptr<Connection> ConnectorImpl::Connect(ConnectParams* params) {
   std::unique_ptr<internal::ConnectionImpl> registry(
       new internal::ConnectionImpl(
           params->target().name(), params->target(), mojom::kInvalidInstanceID,
-          std::move(remote_interfaces), std::move(local_request), request,
-          Connection::State::PENDING));
+          request, Connection::State::PENDING));
+  if (params->exposed_interfaces()) {
+    params->exposed_interfaces()->Bind(std::move(local_request));
+    registry->set_exposed_interfaces(params->exposed_interfaces());
+  } else {
+    std::unique_ptr<InterfaceRegistry> exposed_interfaces(
+        new InterfaceRegistry(registry.get()));
+    exposed_interfaces->Bind(std::move(local_request));
+    registry->SetExposedInterfaces(std::move(exposed_interfaces));
+  }
+  if (params->remote_interfaces()) {
+    params->remote_interfaces()->Bind(std::move(remote_interfaces));
+    registry->set_remote_interfaces(params->remote_interfaces());
+  } else {
+    std::unique_ptr<InterfaceProvider> remote_interface_provider(
+        new InterfaceProvider);
+    remote_interface_provider->Bind(std::move(remote_interfaces));
+    registry->SetRemoteInterfaces(std::move(remote_interface_provider));
+  }
 
   mojom::ShellClientPtr shell_client;
   mojom::PIDReceiverRequest pid_receiver_request;