Take extensions out of Profile into a profile-keyed service, ExtensionSystem.

chrome/browser/extensions/extension_system_factory.h

Index: chrome/browser/extensions/extension_system_factory.h
diff --git a/chrome/browser/extensions/extension_system_factory.h b/chrome/browser/extensions/extension_system_factory.h
new file mode 100644
index 0000000000000000000000000000000000000000..a6c0c9eb51f40571fd7321ffea18c2049432e0e2
--- /dev/null
+++ b/chrome/browser/extensions/extension_system_factory.h
@@ -0,0 +1,56 @@
+// Copyright (c) 2012 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_FACTORY_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_FACTORY_H_
+#pragma once
+
+#include "base/memory/singleton.h"
+#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/profiles/profile_keyed_service_factory.h"
+
+class ExtensionSystem;
+class Profile;
+class ProfileKeyedService;
+
+// ProfileKeyedServiceFactory for ExtensionSystemImpl::Shared.
+// Should not be used except by ExtensionSystem(Factory).
+class ExtensionSystemSharedFactory : public ProfileKeyedServiceFactory {
+ public:
+  static ExtensionSystemImpl::Shared* GetForProfile(Profile* profile);
+
+  static ExtensionSystemSharedFactory* GetInstance();
+
+ private:
+  friend struct DefaultSingletonTraits<ExtensionSystemSharedFactory>;
+
+  ExtensionSystemSharedFactory();
+  virtual ~ExtensionSystemSharedFactory();
+
+  virtual ProfileKeyedService* BuildServiceInstanceFor(
+      Profile* profile) const OVERRIDE;
+  virtual bool ServiceRedirectedInIncognito() OVERRIDE;
+};
+
+// ProfileKeyedServiceFactory for ExtensionSystem.
+class ExtensionSystemFactory : public ProfileKeyedServiceFactory {
+ public:
+  // ProfileKeyedServiceFactory implementation:
+  static ExtensionSystem* GetForProfile(Profile* profile);
+
+  static ExtensionSystemFactory* GetInstance();
+
+ private:
+  friend struct DefaultSingletonTraits<ExtensionSystemFactory>;
+
+  ExtensionSystemFactory();
+  virtual ~ExtensionSystemFactory();
+
+  virtual ProfileKeyedService* BuildServiceInstanceFor(
+      Profile* profile) const OVERRIDE;
+  virtual bool ServiceHasOwnInstanceInIncognito() OVERRIDE;
+  virtual bool ServiceIsCreatedWithProfile() OVERRIDE;
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_FACTORY_H_