Refactor syncable DEVICE_INFO type from ChangeProcessor to SyncableService - Part 2

chrome/browser/sync/glue/device_info_tracker.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_DEVICE_INFO_TRACKER_H_
+#define CHROME_BROWSER_SYNC_GLUE_DEVICE_INFO_TRACKER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "chrome/browser/sync/glue/device_info.h"
+
+namespace browser_sync {
+
+// Interface for tracking synced DeviceInfo.
+class DeviceInfoTracker {
+ public:
+  virtual ~DeviceInfoTracker() {}
+
+  // Observer class for listening to device info changes.
+  class Observer {
+   public:
+    virtual void OnDeviceInfoChange() = 0;
+  };
+
+  // Gets DeviceInfo the synced device with specified client ID.
+  // Returns an empty scoped_ptr if device with the given |client_id| hasn't
+  // been synced.
+  virtual scoped_ptr<DeviceInfo> GetDeviceInfo(
+      const std::string& client_id) const = 0;
+  // Gets DeviceInfo for all synced devices (including the local one).
+  virtual ScopedVector<DeviceInfo> GetAllDeviceInfo() const = 0;
+  // Registers an observer to be called on syncing any updated DeviceInfo.
+  virtual void AddObserver(Observer* observer) = 0;
+  // Unregisters an observer.
+  virtual void RemoveObserver(Observer* observer) = 0;
+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_GLUE_DEVICE_INFO_TRACKER_H_