[Sync] Have SBH tell SyncManager which types to purge

chrome/browser/sync/glue/sync_backend_host.h

 // 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.
 
 #ifndef CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 350 matching lines @@
   };
 
   // Allows tests to perform alternate core initialization work.
   virtual void InitCore(const DoInitializeOptions& options);
 
   // Request the syncer to reconfigure with the specfied params.
   // Virtual for testing.
   virtual void RequestConfigureSyncer(
       syncer::ConfigureReason reason,
       syncer::ModelTypeSet to_download,
+      syncer::ModelTypeSet to_purge,
       syncer::ModelTypeSet to_journal,
       syncer::ModelTypeSet to_unapply,
       syncer::ModelTypeSet to_ignore,
       const syncer::ModelSafeRoutingInfo& routing_info,
       const base::Callback<void(syncer::ModelTypeSet,
                                 syncer::ModelTypeSet)>& ready_task,
       const base::Closure& retry_callback);
 
   // Called when the syncer has finished performing a configuration.
   void FinishConfigureDataTypesOnFrontendLoop(
@@ skipping 196 matching lines @@
   // HandleInitializationCompletedOnFrontendLoop.
   syncer::WeakHandle<syncer::JsBackend> js_backend_;
   syncer::WeakHandle<syncer::DataTypeDebugInfoListener> debug_info_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHost);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_