services: Allow cloning disconnected Connectors.

If the unbound state is invalid, cloning the connector can fail and
returns null. Instead create a new Connector with invalid state to
avoid having callers guard against this case.

R=rockot@chromium.org

Bug: 792340
Change-Id: I39ba3253048f4599586d0fb94d7f1d91404f1ace
Reviewed-on: https://chromium-review.googlesource.com/812498
Commit-Queue: Khushal <khushalsagar@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522371}

services/service_manager/public/cpp/connector.cc

@@ -87,12 +87,11 @@ void Connector::BindInterface(const Identity& target,
 }
 
 std::unique_ptr<Connector> Connector::Clone() {
-  if (!BindConnectorIfNecessary())
-    return nullptr;
-
-  mojom::ConnectorPtr connector;
-  connector_->Clone(mojo::MakeRequest(&connector));
-  return std::make_unique<Connector>(connector.PassInterface());
+  mojom::ConnectorPtrInfo connector;
+  auto request = mojo::MakeRequest(&connector);
+  if (BindConnectorIfNecessary())
+    connector_->Clone(std::move(request));
+  return std::make_unique<Connector>(std::move(connector));
 }
 
 bool Connector::IsBound() const {

services/service_manager/tests/service_manager/service_manager_unittest.cc

@@ -582,4 +582,9 @@ TEST_F(ServiceManagerTest, ClientProcessCapabilityEnforced) {
   EXPECT_EQ(1u, instances().size());
 }
 
+TEST_F(ServiceManagerTest, ClonesDisconnectedConnectors) {
+  Connector connector((mojom::ConnectorPtrInfo()));
+  EXPECT_TRUE(connector.Clone());
+}
+
 }  // namespace service_manager