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/asset_stream_server.cc

@@ -0,0 +1,41 @@
+// 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.
+
+#include "asset_stream_manager/asset_stream_server.h"
+
+#include "asset_stream_manager/grpc_asset_stream_server.h"
+#include "asset_stream_manager/testing_asset_stream_server.h"
+
+namespace cdc_ft {
+
+AssetStreamServer::AssetStreamServer(std::string src_dir,
+                                     DataStoreReader* data_store_reader,
+                                     FileChunkMap* file_chunks) {}
+
+std::unique_ptr<AssetStreamServer> AssetStreamServer::Create(
+    AssetStreamServerType type, std::string src_dir,
+    DataStoreReader* data_store_reader, FileChunkMap* file_chunks,
+    ContentSentHandler content_sent) {
+  switch (type) {
+    case AssetStreamServerType::kGrpc:
+      return std::make_unique<GrpcAssetStreamServer>(src_dir, data_store_reader,
+                                                     file_chunks, content_sent);
+    case AssetStreamServerType::kTest:
+      return std::make_unique<TestingAssetStreamServer>(
+          src_dir, data_store_reader, file_chunks);
+  }
+  assert(false);
+  return nullptr;
+}
+}  // namespace cdc_ft