[Sync] Register USS types with ModelTypeRegistry before download

sync/internal_api/public/engine/model_safe_worker.cc

 // Copyright (c) 2012 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.
 
 #include "sync/internal_api/public/engine/model_safe_worker.h"
 
 #include "base/bind.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
@@ skipping 45 matching lines @@
     case GROUP_DB:
       return "GROUP_DB";
     case GROUP_FILE:
       return "GROUP_FILE";
     case GROUP_HISTORY:
       return "GROUP_HISTORY";
     case GROUP_PASSIVE:
       return "GROUP_PASSIVE";
     case GROUP_PASSWORD:
       return "GROUP_PASSWORD";
+    case GROUP_NON_BLOCKING:
+      return "GROUP_NON_BLOCKING";
     default:
       NOTREACHED();
       return "INVALID";
   }
 }
 
 ModelSafeWorker::ModelSafeWorker(WorkerLoopDestructionObserver* observer)
     : stopped_(false),
       work_done_or_stopped_(false, false),
       observer_(observer),
@@ skipping 113 matching lines @@
       return;
     DCHECK_EQ(base::MessageLoop::current(), working_loop_);
   }
 
   DCHECK(stopped_);
   base::MessageLoop::current()->RemoveDestructionObserver(this);
   unregister_done_callback.Run(GetModelSafeGroup());
 }
 
 }  // namespace syncer