[cast_channel] Move cast_channel related files from //extensions to //components

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::last_channel_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);
-  int id = ++last_channel_id_;
-  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