[Sync] Cleanup all tab sync enabling logic now that its on by default.

BUG=none
TEST=


Review URL: https://chromiumcodereview.appspot.com/10443046

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@139462 0039d316-1c4b-4281-b951-d872f2087c98
MigrationList MakeList(syncable::ModelTypeSet model_types1,
                       syncable::ModelTypeSet model_types2) {
  MigrationList migration_list;
  migration_list.push_back(model_types1);
  migration_list.push_back(model_types2);
  return migration_list;
}

MigrationList MakeList(syncable::ModelTypeSet model_types1,
                       syncable::ModelTypeSet model_types2) {
  MigrationList migration_list;
  migration_list.push_back(model_types1);
  migration_list.push_back(model_types2);
  return migration_list;
}
