sync: Remove dead code related to ClearUserData

chrome/browser/sync/glue/sync_backend_host_core.h

 // Copyright 2013 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_CORE_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_
 
 #include "base/memory/ref_counted.h"
 
 #include "base/timer/timer.h"
@@ skipping 81 matching lines @@
   virtual void OnSyncCycleCompleted(
       const syncer::sessions::SyncSessionSnapshot& snapshot) OVERRIDE;
   virtual void OnInitializationComplete(
       const syncer::WeakHandle<syncer::JsBackend>& js_backend,
       const syncer::WeakHandle<syncer::DataTypeDebugInfoListener>&
           debug_info_listener,
       bool success,
       syncer::ModelTypeSet restored_types) OVERRIDE;
   virtual void OnConnectionStatusChange(
       syncer::ConnectionStatus status) OVERRIDE;
-  virtual void OnStopSyncingPermanently() OVERRIDE;
   virtual void OnActionableError(
       const syncer::SyncProtocolError& sync_error) OVERRIDE;
 
   // SyncEncryptionHandler::Observer implementation.
   virtual void OnPassphraseRequired(
       syncer::PassphraseRequiredReason reason,
       const sync_pb::EncryptedData& pending_keys) OVERRIDE;
   virtual void OnPassphraseAccepted() OVERRIDE;
   virtual void OnBootstrapTokenUpdated(
       const std::string& bootstrap_token,
@@ skipping 173 matching lines @@
   const bool has_sync_setup_completed_;
 
   base::WeakPtrFactory<SyncBackendHostCore> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHostCore);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_