FYI: Control Data + Per-Device Metadata

chrome/browser/sync/sync_prefs.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 "chrome/browser/sync/sync_prefs.h"
 
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "base/values.h"
 #include "build/build_config.h"
@@ skipping 322 matching lines @@
 #endif
 
   pref_service_->RegisterBooleanPref(prefs::kSyncKeepEverythingSynced,
                                      enable_by_default,
                                      PrefService::UNSYNCABLE_PREF);
 
   // Treat bookmarks specially.
   RegisterDataTypePreferredPref(syncer::BOOKMARKS, true);
   for (int i = syncer::PREFERENCES; i < syncer::MODEL_TYPE_COUNT; ++i) {
     const syncer::ModelType type = syncer::ModelTypeFromInt(i);
-    // Also treat nigori specially.
-    if (type == syncer::NIGORI) {
+    // Treat these types specially.
+    if (IsControlType(type)) {
       continue;
     }
     RegisterDataTypePreferredPref(type, enable_by_default);
   }
 
   pref_service_->RegisterBooleanPref(prefs::kSyncManaged,
                                      false,
                                      PrefService::UNSYNCABLE_PREF);
   pref_service_->RegisterStringPref(prefs::kSyncEncryptionBootstrapToken,
                                     "",
@@ skipping 78 matching lines @@
     if (types.Has(i->first))
       types_with_groups.PutAll(i->second);
     else
       types_with_groups.RemoveAll(i->second);
   }
   types_with_groups.RetainAll(registered_types);
   return types_with_groups;
 }
 
 }  // namespace browser_sync