sync: Remove dead code related to ClearUserData

components/sync_driver/sync_frontend.h

 // Copyright 2014 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 COMPONENTS_SYNC_DRIVER_SYNC_FRONTEND_H_
 #define COMPONENTS_SYNC_DRIVER_SYNC_FRONTEND_H_
 
 #include "base/basictypes.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/sync_encryption_handler.h"
@@ skipping 39 matching lines @@
   virtual void OnSyncCycleCompleted() = 0;
 
   // Configure ran into some kind of error. But it is scheduled to be
   // retried.
   virtual void OnSyncConfigureRetry() = 0;
 
   // The status of the connection to the sync server has changed.
   virtual void OnConnectionStatusChange(
       syncer::ConnectionStatus status) = 0;
 
-  // We are no longer permitted to communicate with the server. Sync should
-  // be disabled and state cleaned up at once.
-  virtual void OnStopSyncingPermanently() = 0;
-
   // The syncer requires a passphrase to decrypt sensitive updates. This is
   // called when the first sensitive data type is setup by the user and anytime
   // the passphrase is changed by another synced client. |reason| denotes why
   // the passphrase was required. |pending_keys| is a copy of the
   // cryptographer's pending keys to be passed on to the frontend in order to
   // be cached.
   virtual void OnPassphraseRequired(
       syncer::PassphraseRequiredReason reason,
       const sync_pb::EncryptedData& pending_keys) = 0;
 
@@ skipping 29 matching lines @@
   virtual void OnExperimentsChanged(
       const syncer::Experiments& experiments) = 0;
 
   // Called when the sync cycle returns there is an user actionable error.
   virtual void OnActionableError(const syncer::SyncProtocolError& error) = 0;
 };
 
 }  // namespace browser_sync
 
 #endif  // COMPONENTS_SYNC_DRIVER_SYNC_FRONTEND_H_