Revert 110555 - sync: Remove ModelNeutralExecuteImpl()

chrome/browser/sync/engine/model_changing_syncer_command.cc

 // Copyright (c) 2011 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/engine/model_changing_syncer_command.h"
 
 #include "base/basictypes.h"
 #include "base/callback_old.h"
 #include "chrome/browser/sync/engine/model_safe_worker.h"
 #include "chrome/browser/sync/sessions/status_controller.h"
 #include "chrome/browser/sync/sessions/sync_session.h"
 #include "chrome/browser/sync/util/unrecoverable_error_info.h"
 
 namespace browser_sync {
 
 void ModelChangingSyncerCommand::ExecuteImpl(sessions::SyncSession* session) {
   work_session_ = session;
+  if (!ModelNeutralExecuteImpl(work_session_)) {
+    return;
+  }
 
   // Project the list of active types (i.e., types in the routing
   // info) to a list of groups.
   //
   // TODO(akalin): Make this overrideable by subclasses (who might be
   // working on a subset of |active_groups|).  (See
   // http://crbug.com/97832.)
   std::set<ModelSafeGroup> active_groups;
   const ModelSafeRoutingInfo& routing_info = session->routing_info();
   for (ModelSafeRoutingInfo::const_iterator it = routing_info.begin();
@@ skipping 21 matching lines @@
         // We wait until the callback is executed. So it is safe to use
         // unretained.
         base::Unretained(this));
 
     // TODO(lipalani): Check the return value for an unrecoverable error.
     ignore_result(worker->DoWorkAndWaitUntilDone(c));
 
   }
 }
 
+bool ModelChangingSyncerCommand::ModelNeutralExecuteImpl(
+    sessions::SyncSession* session) {
+  return true;
+}
+
 }  // namespace browser_sync