[Chromecast] Use a single underlying connection to the Mojo broker

Bug: internal b/158335072
Change-Id: Ic3413ccd9722a8fadc05fb36a8a2e9c821cf65ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2240275Reviewed-by: Michael Spang <spang@chromium.org>
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780326}

chromecast/external_mojo/external_service_support/external_connector_impl.h

@@ -5,6 +5,7 @@
 #ifndef CHROMECAST_EXTERNAL_MOJO_EXTERNAL_SERVICE_SUPPORT_EXTERNAL_CONNECTOR_IMPL_H_
 #define CHROMECAST_EXTERNAL_MOJO_EXTERNAL_SERVICE_SUPPORT_EXTERNAL_CONNECTOR_IMPL_H_
 
+#include <cstdint>
 #include <memory>
 #include <string>
 #include <vector>
@@ -21,12 +22,16 @@ namespace chromecast {
 namespace external_service_support {
 
 class ExternalConnectorImpl : public ExternalConnector {
+  class BrokerConnection;
+
  public:
   explicit ExternalConnectorImpl(const std::string& broker_path);
   explicit ExternalConnectorImpl(
-      const std::string& broker_path,
+      scoped_refptr<BrokerConnection> broker_connection);
+  // For in-process connectors only.
+  explicit ExternalConnectorImpl(
       mojo::PendingRemote<external_mojo::mojom::ExternalConnector>
-          connector_pending_remote);
+          pending_remote);
   ~ExternalConnectorImpl() override;
 
   // ExternalConnector implementation:
@@ -55,27 +60,18 @@ class ExternalConnectorImpl : public ExternalConnector {
   void BindInterfaceImmediately(const std::string& service_name,
                                 const std::string& interface_name,
                                 mojo::ScopedMessagePipeHandle interface_pipe);
+  void Connect();
   void OnMojoDisconnect();
-  bool BindConnectorIfNecessary();
-  void InitializeBrokerConnection();
-  void AttemptBrokerConnection();
+  void BindConnectorIfNecessary();
 
-  std::string broker_path_;
+  const scoped_refptr<BrokerConnection> broker_connection_;
 
+  int64_t connection_token_ = 0;
+  mojo::PendingRemote<external_mojo::mojom::ExternalConnector> pending_remote_;
   mojo::Remote<external_mojo::mojom::ExternalConnector> connector_;
 
   base::CallbackList<void()> error_callbacks_;
 
-  // If connecting to a broker, |connector_pending_receiver_for_broker_| is used
-  // to keep |connector_| bound while waiting for the broker.
-  mojo::PendingReceiver<external_mojo::mojom::ExternalConnector>
-      connector_pending_receiver_for_broker_;
-
-  // If cloned, |connector_pending_remote_from_clone_| is stored until an IO
-  // operation is performed to ensure it happens on the correct sequence.
-  mojo::PendingRemote<external_mojo::mojom::ExternalConnector>
-      connector_pending_remote_from_clone_;
-
   SEQUENCE_CHECKER(sequence_checker_);
 
   base::WeakPtrFactory<ExternalConnectorImpl> weak_factory_{this};

chromecast/external_mojo/external_service_support/standalone_mojo_broker.cc

@@ -44,7 +44,7 @@ int main(int argc, char** argv) {
       chromecast::external_mojo::GetBrokerPath());
 
   chromecast::external_service_support::ExternalConnectorImpl tracing_connector(
-      chromecast::external_mojo::GetBrokerPath(), broker.CreateConnector());
+      broker.CreateConnector());
   auto tracing_client =
       chromecast::external_service_support::TracingClient::Create(
           &tracing_connector);