Make the "Tabs" item on about:sync non-yellow

sync/syncable/model_type.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/base/model_type.h"
 
 #include "base/strings/string_split.h"
 #include "base/values.h"
 #include "sync/protocol/app_notification_specifics.pb.h"
 #include "sync/protocol/app_setting_specifics.pb.h"
@@ skipping 1039 matching lines @@
     return true;
   }
   *model_type = UNSPECIFIED;
   return false;
 }
 
 bool IsRealDataType(ModelType model_type) {
   return model_type >= FIRST_REAL_MODEL_TYPE && model_type < MODEL_TYPE_COUNT;
 }
 
+bool IsProxyType(ModelType model_type) {
+  return model_type >= FIRST_PROXY_TYPE && model_type <= LAST_PROXY_TYPE;
+}
+
 bool IsActOnceDataType(ModelType model_type) {
   return model_type == HISTORY_DELETE_DIRECTIVES;
 }
 
 }  // namespace syncer