Add LwwRegister CRDT

blimp/helium/syncable_common.h

 // Copyright 2016 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 "blimp/common/blob_cache/mock_blob_cache.h"
+#ifndef BLIMP_HELIUM_SYNCABLE_COMMON_H_
+#define BLIMP_HELIUM_SYNCABLE_COMMON_H_
 
 namespace blimp {
+namespace helium {
 
-MockBlobCache::MockBlobCache() {}
+enum class Peer { CLIENT, ENGINE };
 
-MockBlobCache::~MockBlobCache() {}
+}  // namespace helium
+}  // namespace blimp
 
-}  // namespace blimp
+#endif  // BLIMP_HELIUM_SYNCABLE_COMMON_H_