Releasing the former Stadia file transfer tools

The tools allow efficient and fast synchronization of large directory
trees from a Windows workstation to a Linux target machine.

cdc_rsync* support efficient copy of files by using content-defined
chunking (CDC) to identify chunks within files that can be reused.

asset_stream_manager + cdc_fuse_fs support efficient streaming of a
local directory to a remote virtual file system based on FUSE. It also
employs CDC to identify and reuse unchanged data chunks.

asset_stream_manager/session_management_server.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ASSET_STREAM_MANAGER_SESSION_MANAGEMENT_SERVER_H_
+#define ASSET_STREAM_MANAGER_SESSION_MANAGEMENT_SERVER_H_
+
+#include <memory>
+
+#include "absl/status/status.h"
+
+namespace grpc {
+class Server;
+class Service;
+}  // namespace grpc
+
+namespace cdc_ft {
+
+class SessionManager;
+class ProcessFactory;
+
+// gRPC server for managing streaming sessions. Contains these services:
+// - LocalAssetsStreamManager
+// - Background
+class SessionManagementServer {
+ public:
+  SessionManagementServer(grpc::Service* session_service,
+                          grpc::Service* background_service,
+                          SessionManager* session_manager);
+  ~SessionManagementServer();
+
+  // Starts the server on the local port |port|.
+  absl::Status Start(int port);
+
+  // Waits until ProcessManager issues an Exit() request to the background
+  // service.
+  void RunUntilShutdown();
+
+  // Shuts down the session manager and the server.
+  absl::Status Shutdown();
+
+ private:
+  grpc::Service* session_service_;
+  grpc::Service* background_service_;
+  SessionManager* const session_manager_;
+  std::unique_ptr<grpc::Server> server_;
+};
+
+}  // namespace cdc_ft
+
+#endif  // ASSET_STREAM_MANAGER_SESSION_MANAGEMENT_SERVER_H_