[cros] Add checkbox for toggling data roaming setting.

chrome/browser/chromeos/user_cros_settings_provider.h

 // Copyright (c) 2010 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_USER_CROS_SETTINGS_PROVIDER_H_
 #define CHROME_BROWSER_CHROMEOS_USER_CROS_SETTINGS_PROVIDER_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "chrome/browser/chromeos/cros_settings_provider.h"
 #include "chrome/browser/chromeos/login/signed_settings_helper.h"
 
 class ListValue;
 class PrefService;
 class Task;
 
 namespace chromeos {
 
+// CrosSettingsProvider implementation that works with SignedSettings.
+// TODO(nkostylev): Rename this class to indicate that it is
+// SignedSettings specific.
 class UserCrosSettingsProvider : public CrosSettingsProvider {
  public:
   UserCrosSettingsProvider();
   virtual ~UserCrosSettingsProvider() {}
 
   // Registers cached users settings in preferences.
   static void RegisterPrefs(PrefService* local_state);
 
   // Methods to use when trusted (signature verified) values are required.
   // Return true if subsequent call to corresponding cached_* getter shall
   // return trusted value.
   // Return false if trusted values are unavailable at a moment.
   // In latter case passed task will be posted when ready.
   bool RequestTrustedAllowGuest(Task* callback);
   bool RequestTrustedAllowNewUser(Task* callback);
+  bool RequestTrustedDataRoamingEnabled(Task* callback);
   bool RequestTrustedShowUsersOnSignin(Task* callback);
   bool RequestTrustedOwner(Task* callback);
 
   // Helper functions to access cached settings.
   static bool cached_allow_guest();
   static bool cached_allow_new_user();
+  static bool cached_data_roaming_enabled();
   static bool cached_show_users_on_signin();
   static const ListValue* cached_whitelist();
   static std::string cached_owner();
 
   // Returns true if given email is in user whitelist.
   // Note this function is for display purpose only and should use
   // CheckWhitelist op for the real whitelist check.
   static bool IsEmailInCachedWhitelist(const std::string& email);
 
   // CrosSettingsProvider implementation.
   virtual bool Get(const std::string& path, Value** out_value) const;
   virtual bool HandlesSetting(const std::string& path);
 
   void WhitelistUser(const std::string& email);
   void UnwhitelistUser(const std::string& email);
 
   // Updates cached value of the owner.
   static void UpdateCachedOwner(const std::string& email);
 
  private:
   // CrosSettingsProvider implementation.
   virtual void DoSet(const std::string& path, Value* value);
 
   DISALLOW_COPY_AND_ASSIGN(UserCrosSettingsProvider);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_USER_CROS_SETTINGS_PROVIDER_H_