[Sync] Add support for proxy types

chrome/browser/sync/backend_migrator.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/backend_migrator.h"
 
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
 #include "base/tracked_objects.h"
 #include "chrome/browser/sync/profile_sync_service.h"
@@ skipping 28 matching lines @@
 }
 
 // Helper macros to log with the syncer thread name; useful when there
 // are multiple syncer threads involved.
 
 #define SLOG(severity) LOG(severity) << name_ << ": "
 
 #define SDVLOG(verbose_level) DVLOG(verbose_level) << name_ << ": "
 
 void BackendMigrator::MigrateTypes(syncer::ModelTypeSet types) {
+  if (!syncer::Intersection(types, syncer::VirtualTypes()).Empty()) {
+    LOG(WARNING) << "Virtual type migration attempted, dropping local types.";
+    types.RemoveAll(syncer::VirtualTypes());
+  }
   const ModelTypeSet old_to_migrate = to_migrate_;
   to_migrate_.PutAll(types);
   SDVLOG(1) << "MigrateTypes called with " << ModelTypeSetToString(types)
            << ", old_to_migrate = " << ModelTypeSetToString(old_to_migrate)
           << ", to_migrate_ = " << ModelTypeSetToString(to_migrate_);
   if (old_to_migrate.Equals(to_migrate_)) {
     SDVLOG(1) << "MigrateTypes called with no new types; ignoring";
     return;
   }
 
@@ skipping 157 matching lines @@
 
 syncer::ModelTypeSet BackendMigrator::GetPendingMigrationTypesForTest() const {
   return to_migrate_;
 }
 
 #undef SDVLOG
 
 #undef SLOG
 
 };  // namespace browser_sync