ExtensionSystem cleanup part 2

apps/shell/browser/shell_extension_system_factory.cc

+// Copyright 2014 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 "apps/shell/browser/shell_extension_system_factory.h"
+
+#include "apps/shell/browser/shell_extension_system.h"
+#include "components/browser_context_keyed_service/browser_context_dependency_manager.h"
+#include "extensions/browser/extension_prefs_factory.h"
+#include "extensions/browser/extension_registry_factory.h"
+
+using content::BrowserContext;
+
+namespace extensions {
+
+ExtensionSystem* ShellExtensionSystemFactory::GetForBrowserContext(
+    BrowserContext* context) {
+  return static_cast<ShellExtensionSystem*>(
+      GetInstance()->GetServiceForBrowserContext(context, true));
+}
+
+// static
+ShellExtensionSystemFactory* ShellExtensionSystemFactory::GetInstance() {
+  return Singleton<ShellExtensionSystemFactory>::get();
+}
+
+ShellExtensionSystemFactory::ShellExtensionSystemFactory()
+    : ExtensionSystemProvider("ShellExtensionSystem",
+                              BrowserContextDependencyManager::GetInstance()) {
+  DependsOn(ExtensionPrefsFactory::GetInstance());
+  DependsOn(ExtensionRegistryFactory::GetInstance());
+}
+
+ShellExtensionSystemFactory::~ShellExtensionSystemFactory() {}
+
+BrowserContextKeyedService*
+ShellExtensionSystemFactory::BuildServiceInstanceFor(BrowserContext* context)
+    const {
+  return new ShellExtensionSystem(context);
+}
+
+BrowserContext* ShellExtensionSystemFactory::GetBrowserContextToUse(
+    BrowserContext* context) const {
+  // Use a separate instance for incognito.
+  return context;
+}
+
+bool ShellExtensionSystemFactory::ServiceIsCreatedWithBrowserContext() const {
+  return true;
+}
+
+}  // namespace extensions