sync: Remove ClearUserData command.

sync/engine/sync_engine_event.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 SYNC_ENGINE_SYNC_ENGINE_EVENT_H_
 #define SYNC_ENGINE_SYNC_ENGINE_EVENT_H_
 #pragma once
 
 #include <string>
 
@@ skipping 23 matching lines @@
 
     // New token in updated_token.
     UPDATED_TOKEN,
 
     // This is sent after the Syncer (and SyncerThread) have initiated self
     // halt due to no longer being permitted to communicate with the server.
     // The listener should sever the sync / browser connections and delete sync
     // data (i.e. as if the user clicked 'Stop Syncing' in the browser.
     STOP_SYNCING_PERMANENTLY,
 
-    // These events are sent to indicate when we know the clearing of
-    // server data have failed or succeeded.
-    CLEAR_SERVER_DATA_SUCCEEDED,
-    CLEAR_SERVER_DATA_FAILED,
-
     // This event is sent when we receive an actionable error. It is upto
     // the listeners to figure out the action to take using the snapshot sent.
     ACTIONABLE_ERROR,
   };
 
   explicit SyncEngineEvent(EventCause cause);
   ~SyncEngineEvent();
 
   EventCause what_happened;
 
   // The last session used for syncing.
   sessions::SyncSessionSnapshot snapshot;
 
   // Update-Client-Auth returns a new token for sync use.
   std::string updated_token;
 };
 
 class SyncEngineEventListener {
  public:
   // TODO(tim): Consider splitting this up to multiple callbacks, rather than
   // have to do Event e(type); OnSyncEngineEvent(e); at all callsites,
   virtual void OnSyncEngineEvent(const SyncEngineEvent& event) = 0;
  protected:
   virtual ~SyncEngineEventListener() {}
 };
 
 }  // namespace browser_sync
 
 #endif  // SYNC_ENGINE_SYNC_ENGINE_EVENT_H_