Add non-blocking sync code to ProfileSyncService

chrome/browser/sync/glue/sync_backend_host_core.h

 // 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_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_
 
 #include "base/memory/ref_counted.h"
 
 #include "base/timer/timer.h"
@@ skipping 193 matching lines @@
   // on the IO thread. Must be removed from IO thread.
 
   syncer::SyncManager* sync_manager() { return sync_manager_.get(); }
 
   SyncedDeviceTracker* synced_device_tracker() {
     return synced_device_tracker_.get();
   }
 
   void SetForwardProtocolEvents(bool forward);
 
+  // Returns handle to sync functionality used by non-blocking sync types.
+  // Should only be called when the backend is initialized.
+  syncer::SyncCoreProxy GetSyncCoreProxy();
+
   // Delete the sync data folder to cleanup backend data.  Happens the first
   // time sync is enabled for a user (to prevent accidentally reusing old
   // sync databases), as well as shutdown when you're no longer syncing.
   void DeleteSyncDataFolder();
 
   // We expose this member because it's required in the construction of the
   // HttpBridgeFactory.
   syncer::CancelationSignal* GetRequestContextCancelationSignal() {
     return &release_request_context_signal_;
   }
@@ skipping 68 matching lines @@
   bool forward_protocol_events_;
 
   base::WeakPtrFactory<SyncBackendHostCore> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHostCore);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_