[cast_channel] Make CastSocket not inherit from ApiResource

extensions/browser/api/cast_channel/cast_socket_service.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 "extensions/browser/api/cast_channel/cast_socket_service.h"
+
+#include "base/memory/ptr_util.h"
+
+namespace extensions {
+namespace api {
+namespace cast_channel {
+
+int CastSocketRegistry::id_ = 0;
+
+CastSocketRegistry::CastSocketRegistry() = default;
+
+CastSocketRegistry::~CastSocketRegistry() {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+}
+
+int CastSocketRegistry::AddSocket(std::unique_ptr<CastSocket> socket) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  DCHECK(socket);
+  socket->set_id(++id_);
+  sockets_.insert(std::make_pair(id_, std::move(socket)));
+  return id_;
+}
+
+std::unique_ptr<CastSocket> CastSocketRegistry::RemoveSocket(int channel_id) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  DCHECK(channel_id > 0);
+  auto socket_it = sockets_.find(channel_id);
+
+  std::unique_ptr<CastSocket> socket;
+  if (socket_it != sockets_.end()) {
+    socket = std::move(socket_it->second);
+    sockets_.erase(socket_it);
+  }
+  return socket;
+}
+
+CastSocket* CastSocketRegistry::GetSocket(int channel_id) const {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  DCHECK(channel_id > 0);
+  const auto& socket_it = sockets_.find(channel_id);
+  return socket_it == sockets_.end() ? nullptr : socket_it->second.get();
+}
+
+CastSocketService::CastSocketService() = default;
+CastSocketService::~CastSocketService() = default;
+
+CastSocketRegistry* CastSocketService::GetOrCreateSocketRegistry() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (!sockets_)
+    sockets_.reset(new CastSocketRegistry());
+  return sockets_.get();
+}
+
+}  // namespace cast_channel
+}  // namespace api
+}  // namespace extensions