[Chromoting] Add DataChannelManager to manage optional incoming data channels

remoting/protocol/data_channel_manager.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "remoting/protocol/data_channel_manager.h"
+
+#include <utility>
+
+#include "base/logging.h"
+#include "remoting/protocol/message_pipe.h"
+
+namespace remoting {
+namespace protocol {
+
+DataChannelManager::DataChannelManager() = default;
+DataChannelManager::~DataChannelManager() = default;
+
+void DataChannelManager::RegisterCreateHandlerCallback(
+    const std::string& prefix,
+    CreateHandlerCallback constructor) {
+  DCHECK(!prefix.empty());
+  DCHECK(constructor);
+  constructors_.push_back(std::make_pair(prefix, constructor));
+}
+
+bool DataChannelManager::OnIncomingDataChannel(
+    const std::string& name,
+    std::unique_ptr<MessagePipe> pipe) {
+  for (auto& constructor : constructors_) {
+    if (name.find(constructor.first) == 0) {
+      constructor.second.Run(name, std::move(pipe));
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace protocol
+}  // namespace remoting