Refactor syncable DEVICE_INFO type from ChangeProcessor to SyncableService - Part 2

chrome/browser/sync/glue/device_info_tracker.h

Index: chrome/browser/sync/glue/device_info_tracker.h
diff --git a/chrome/browser/sync/glue/device_info_tracker.h b/chrome/browser/sync/glue/device_info_tracker.h
new file mode 100644
index 0000000000000000000000000000000000000000..b364cc03312ff09f390e93c670cac5f7d82c2b1f
--- /dev/null
+++ b/chrome/browser/sync/glue/device_info_tracker.h
@@ -0,0 +1,39 @@
+// 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/callback_list.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:
+  typedef base::CallbackList<void(void)>::Subscription Subscription;
+
+  virtual ~DeviceInfoTracker() {}
+
+  // 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 callback to be called on syncing any updated
+  // DeviceInfo.  The callback remains registered until the returned
+  // Subscription is destroyed, which must occur before this object
+  // is destroyed.
+  virtual scoped_ptr<Subscription> RegisterOnDeviceInfoChangedCallback(
+      const base::Closure& callback) = 0;
+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_GLUE_DEVICE_INFO_TRACKER_H_