[cast_channel] Make CastSocket not inherit from ApiResource

extensions/browser/api/cast_channel/cast_socket_service_factory.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_factory.h"
+
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "extensions/browser/api/cast_channel/cast_socket_service.h"
+
+namespace extensions {
+namespace api {
+namespace cast_channel {
+
+using content::BrowserContext;
+
+namespace {
+
+base::LazyInstance<CastSocketServiceFactory>::DestructorAtExit service_factory =
+    LAZY_INSTANCE_INITIALIZER;
+}  // namespace
+
+// static
+CastSocketService* CastSocketServiceFactory::GetForBrowserContext(
+    BrowserContext* context) {
+  DCHECK(context);
+  // GetServiceForBrowserContext returns a KeyedService hence the static_cast<>
+  // to return a pointer to CastSocketService.
+  return static_cast<CastSocketService*>(
+      service_factory.Get().GetServiceForBrowserContext(context, true));
+}
+
+// static
+CastSocketServiceFactory* CastSocketServiceFactory::GetInstance() {
+  return &service_factory.Get();
+}
+
+CastSocketServiceFactory::CastSocketServiceFactory()
+    : BrowserContextKeyedServiceFactory(
+          "CastSocketService",
+          BrowserContextDependencyManager::GetInstance()) {}
+
+CastSocketServiceFactory::~CastSocketServiceFactory() {}
+
+content::BrowserContext* CastSocketServiceFactory::GetBrowserContextToUse(
+    content::BrowserContext* context) const {
+  return context;
+}
+
+KeyedService* CastSocketServiceFactory::BuildServiceInstanceFor(
+    BrowserContext* context) const {
+  return new CastSocketService();
+}
+
+}  // namespace cast_channel
+}  // namespace api
+}  // namespace extensions