[Sync] Add support for proxy types

sync/engine/store_timestamps_command_unittest.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 "base/basictypes.h"
 #include "sync/engine/store_timestamps_command.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/test/engine/syncer_command_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 54 matching lines @@
 
   EXPECT_TRUE(
       forward_progress_types.Equals(
           ModelTypeSet(BOOKMARKS, HISTORY_DELETE_DIRECTIVES)));
 
   EXPECT_EQ("token1", GetProgessMarkerToken(BOOKMARKS));
   EXPECT_EQ("token2", GetProgessMarkerToken(HISTORY_DELETE_DIRECTIVES));
 
   ModelTypeSet non_forward_progress_types =
       Difference(ModelTypeSet::All(), forward_progress_types);
+  non_forward_progress_types.RemoveAll(VirtualTypes());
   for (ModelTypeSet::Iterator it = non_forward_progress_types.First();
        it.Good(); it.Inc()) {
     EXPECT_TRUE(GetProgessMarkerToken(it.Get()).empty());
   }
 }
 
 }  // namespace
 
 }  // namespace syncer