Sync: Change Local IDs to GUID based to avoid ID collision

sync/syncable/in_memory_directory_backing_store.h

 // Copyright 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.
 
 #ifndef SYNC_SYNCABLE_IN_MEMORY_DIRECTORY_BACKING_STORE_H_
 #define SYNC_SYNCABLE_IN_MEMORY_DIRECTORY_BACKING_STORE_H_
 
 #include "sync/syncable/directory_backing_store.h"
 #include "sync/base/sync_export.h"
 
@@ skipping 11 matching lines @@
 // TestDirectoryBackingStore.
 class SYNC_EXPORT_PRIVATE InMemoryDirectoryBackingStore
     : public DirectoryBackingStore {
  public:
   explicit InMemoryDirectoryBackingStore(const std::string& dir_name);
   DirOpenResult Load(Directory::MetahandlesMap* handles_map,
                      JournalIndex* delete_journals,
                      MetahandleSet* metahandles_to_purge,
                      Directory::KernelLoadInfo* kernel_load_info) override;
 
-  void request_consistent_cache_guid() {
-    consistent_cache_guid_requested_ = true;
-  }
-
  private:
-  bool consistent_cache_guid_requested_;
-
   DISALLOW_COPY_AND_ASSIGN(InMemoryDirectoryBackingStore);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // SYNC_SYNCABLE_IN_MEMORY_DIRECTORY_BACKING_STORE_H_