Add LwwRegister CRDT

blimp/helium/syncable_common.h

Index: blimp/helium/syncable_common.h
diff --git a/blimp/common/blob_cache/mock_blob_cache.cc b/blimp/helium/syncable_common.h
similarity index 51%
copy from blimp/common/blob_cache/mock_blob_cache.cc
copy to blimp/helium/syncable_common.h
index 4cf10522588b680929bcbe0a751f6e8dbff32b4f..6e47dfd345738fa08334469bf2943a4efbc27841 100644
--- a/blimp/common/blob_cache/mock_blob_cache.cc
+++ b/blimp/helium/syncable_common.h
@@ -2,12 +2,15 @@
 // 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() {}
-
-MockBlobCache::~MockBlobCache() {}
+enum class Peer { CLIENT, ENGINE };
 
+}  // namespace helium
 }  // namespace blimp
+
+#endif  // BLIMP_HELIUM_SYNCABLE_COMMON_H_