sync: Set explicit protocol_version on commit

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 70 matching lines @@
     MockConnectionManager::MidCommitObserver* observer) {
     mid_commit_observer_ = observer;
 }
 
 bool MockConnectionManager::PostBufferToPath(PostBufferParams* params,
     const string& path,
     const string& auth_token,
     csync::ScopedServerStatusWatcher* watcher) {
   ClientToServerMessage post;
   CHECK(post.ParseFromString(params->buffer_in));
+  CHECK(post.has_protocol_version());
   last_request_.CopyFrom(post);
   client_stuck_ = post.sync_problem_detected();
   ClientToServerResponse response;
   response.Clear();
 
   if (directory_) {
     // If the Directory's locked when we do this, it's a problem as in normal
     // use this function could take a while to return because it accesses the
     // network. As we can't test this we do the next best thing and hang here
     // when there's an issue.
@@ skipping 485 matching lines @@
   server_reachable_ = false;
 }
 
 void MockConnectionManager::UpdateConnectionStatus() {
   if (!server_reachable_) {
     server_status_ = HttpResponse::CONNECTION_UNAVAILABLE;
   } else {
     server_status_ = HttpResponse::SERVER_CONNECTION_OK;
   }
 }