sync: Loop committing items without downloading updates

sync/test/engine/mock_connection_manager.cc

 // 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.
 //
 // Mock ServerConnectionManager class for use in client regression tests.
 
 #include "sync/test/engine/mock_connection_manager.h"
 
 #include <map>
 
@@ skipping 150 matching lines @@
     }
 
     if (fail_with_auth_invalid_)
       response.set_error_code(SyncEnums::AUTH_INVALID);
   }
 
   response.SerializeToString(&params->buffer_out);
   if (post.message_contents() == ClientToServerMessage::COMMIT &&
       !mid_commit_callback_.is_null()) {
     mid_commit_callback_.Run();
+    mid_commit_callback_.Reset();
   }
   if (mid_commit_observer_) {
     mid_commit_observer_->Observe();
   }
 
   return result;
 }
 
 sync_pb::GetUpdatesResponse* MockConnectionManager::GetUpdateResponse() {
   if (update_queue_.empty()) {
@@ skipping 442 matching lines @@
   server_reachable_ = false;
 }
 
 void MockConnectionManager::UpdateConnectionStatus() {
   if (!server_reachable_) {
     server_status_ = HttpResponse::CONNECTION_UNAVAILABLE;
   } else {
     server_status_ = HttpResponse::SERVER_CONNECTION_OK;
   }
 }