Sync: Refactoring of DEVICE_INFO syncable type - Part 1

chrome/browser/sync/glue/local_device_info_provider.h

+// 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.
+
+#ifndef CHROME_BROWSER_SYNC_GLUE_LOCAL_DEVICE_INFO_PROVIDER_H_
+#define CHROME_BROWSER_SYNC_GLUE_LOCAL_DEVICE_INFO_PROVIDER_H_
+
+#include <string>
+#include "base/callback_list.h"
+
+namespace browser_sync {
+
+class DeviceInfo;
+
+// Interface for providing sync specific informaiton about the
+// local device.
+class LocalDeviceInfoProvider {
+ public:
+  typedef base::CallbackList<void(void)>::Subscription Subscription;
+
+  virtual ~LocalDeviceInfoProvider() {}
+
+  // Returns sync's representation of the local device info;
+  // NULL if the device info is unavailable.
+  // The returned object is fully owned by LocalDeviceInfoProvider (must not
+  // be freed by the caller). It remains valid until LocalDeviceInfoProvider
+  // is destroyed.
+  virtual const DeviceInfo* GetLocalDeviceInfo() const = 0;
+
+  // Returns a GUID string used for creation of the machine tag for
+  // this local session; an empty sting if LocalDeviceInfoProvider hasn't been
+  // initialized yet.
+  virtual std::string GetLocalSyncCacheGUID() const = 0;
+
+  // Starts initializing local device info.
+  virtual void Initialize(const std::string& cache_guid) = 0;
+
+  // Registers a callback to be called when local device info becomes available.
+  // The callback will remain registered until the
+  // returned Subscription is destroyed, which must occur before the
+  // CallbackList is destroyed.
+  virtual scoped_ptr<Subscription> RegisterOnInitializedCallback(
+      const base::Closure& callback) = 0;
+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_GLUE_LOCAL_DEVICE_INFO_PROVIDER_H_