Refactor OAuth2TokenService to have profile- and device-based implementations.

chrome/browser/chromeos/settings/device_oauth2_token_service_factory.h

+// Copyright 2013 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_CHROMEOS_SETTINGS_DEVICE_OAUTH2_TOKEN_SERVICE_FACTORY_H_
+#define CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_OAUTH2_TOKEN_SERVICE_FACTORY_H_
+
+#include "base/basictypes.h"
+
+namespace chromeos {
+
+class DeviceOAuth2TokenService;
+
+class DeviceOAuth2TokenServiceFactory {
+ public:
+  // Returns the instance of the DeviceOAuth2TokenService singleton.
+  // May return null during browser startup and shutdown.  Do not hold
+  // the pointer returned by this method; call this method every time
+  // and check for null to handle the case where this instance is destroyed
+  // during shutdown.
+  static DeviceOAuth2TokenService* Get();
+
+ private:
+  friend class ChromeBrowserMainPartsChromeos;
+
+  DeviceOAuth2TokenServiceFactory();
+
+  // Called by ChromeBrowserMainPartsChromeOS in order to bootstrap our
+  // DeviceOAuth2TokenService instance after the required global data is
+  // available (local state and request context getter).

[brettw, 2013/04/05 21:58:03]

Can you state the requirements for when shutdown should be called in the comment
here?

+  static void Initialize();
+  static void Shutdown();
+
+  DISALLOW_COPY_AND_ASSIGN(DeviceOAuth2TokenServiceFactory);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_OAUTH2_TOKEN_SERVICE_FACTORY_H_