Add ManagedUserSharedSettingsService.

chrome/browser/managed_mode/managed_user_shared_settings_service.h

Index: chrome/browser/managed_mode/managed_user_shared_settings_service.h
diff --git a/chrome/browser/managed_mode/managed_user_shared_settings_service.h b/chrome/browser/managed_mode/managed_user_shared_settings_service.h
new file mode 100644
index 0000000000000000000000000000000000000000..35c9818060b719511a4d01e6449e6e98990c6369
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+++ b/chrome/browser/managed_mode/managed_user_shared_settings_service.h
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+// 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_MANAGED_MODE_MANAGED_USER_SHARED_SETTINGS_SERVICE_H_
+#define CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_SHARED_SETTINGS_SERVICE_H_
+
+#include "base/callback.h"
+#include "base/callback_list.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/managed_mode/managed_users.h"
+#include "components/browser_context_keyed_service/browser_context_keyed_service.h"
+#include "sync/api/syncable_service.h"
+
+class PrefService;
+
+namespace base {
+class DictionaryValue;
+class Value;
+}
+
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
+// ManagedUserSharedSettingsService syncs settings (as key-value pairs) that can
+// be modified both by a supervised user and their manager.
+// A supervised user can only modify their own settings, whereas a manager can
+// modify settings for all their supervised users.
+//
+// The shared settings are stored in the user preferences in a multi-level
+// dictionary. The first level is the MU ID, the second level is the key for the
+// setting, and the third level is a dictionary with a "value" key for the value
+// and an "acknowledged" flag, which is used to wait for the Sync server to
+// acknowledge that it has seen a setting change (see
+// ManagedUserSharedSettingsUpdate for how to use this).
+class ManagedUserSharedSettingsService : public BrowserContextKeyedService,
+                                         public syncer::SyncableService {
+ public:
+  // Called whenever a setting changes (see Subscribe() below).
+  typedef base::Callback<void(const std::string& /* mu_id */,
+                              const std::string& /* key */)> ChangeCallback;
+  typedef base::CallbackList<
+      void(const std::string& /* mu_id */, const std::string& /* key */)>
+      ChangeCallbackList;
+
+  // This constructor is public only for testing. Use
+  // |ManagedUserSyncServiceFactory::GetForProfile(...)| instead to get an
+  // instance of this service in production code.
+  explicit ManagedUserSharedSettingsService(PrefService* prefs);
+  virtual ~ManagedUserSharedSettingsService();
+
+  // Returns the value for the given |key| and the supervised user identified by
+  // |mu_id|. If either the supervised user or the key does not exist, NULL is
+  // returned. Note that if the profile that owns this service belongs to a
+  // supervised user, callers will only see settings for their own |mu_id|, i.e.
+  // a non-matching |mu_id| is treated as non-existent.
+  const base::Value* GetValue(const std::string& mu_id, const std::string& key);
+
+  // Sets the value for the given |key| and the supervised user identified by
+  // |mu_id|. If the profile that owns this service belongs to a supervised
+  // user, |mu_id| must be their own.
+  void SetValue(const std::string& mu_id,
+                const std::string& key,
+                const base::Value& value);
+
+  // Subscribes to changes in the synced settings. The callback will be notified
+  // whenever any setting for any supervised user is changed via Sync (but not
+  // for local changes). Subscribers should filter the settings and users they
+  // are interested in with the |mu_id| and |key| parameters to the callback.
+  scoped_ptr<ChangeCallbackList::Subscription> Subscribe(
+      const ChangeCallback& cb);
+
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
+  // Public for testing.
+  void SetValueInternal(const std::string& mu_id,
+                        const std::string& key,
+                        const base::Value& value,
+                        bool acknowledged);
+
+  // Public for testing.
+  static syncer::SyncData CreateSyncDataForSetting(const std::string& mu_id,
+                                                   const std::string& key,
+                                                   const base::Value& value,
+                                                   bool acknowledged);
+
+  // BrowserContextKeyedService implementation:
+  virtual void Shutdown() OVERRIDE;
+
+  // SyncableService implementation:
+  virtual syncer::SyncMergeResult MergeDataAndStartSyncing(
+      syncer::ModelType type,
+      const syncer::SyncDataList& initial_sync_data,
+      scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
+      scoped_ptr<syncer::SyncErrorFactory> error_handler) OVERRIDE;
+  virtual void StopSyncing(syncer::ModelType type) OVERRIDE;
+  virtual syncer::SyncDataList GetAllSyncData(syncer::ModelType type) const
+      OVERRIDE;
+  virtual syncer::SyncError ProcessSyncChanges(
+      const tracked_objects::Location& from_here,
+      const syncer::SyncChangeList& change_list) OVERRIDE;
+
+ private:
+  friend class ManagedUserSharedSettingsUpdate;
+
+  scoped_ptr<syncer::SyncChangeProcessor> sync_processor_;
+  scoped_ptr<syncer::SyncErrorFactory> error_handler_;
+
+  ChangeCallbackList callbacks_;
+
+  PrefService* prefs_;
+};
+
+#endif  // CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_SHARED_SETTINGS_SERVICE_H_