[Sync] Made some sync session member functions const

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"
@@ skipping 27 matching lines @@
   for (size_t i = 0; i < session->workers().size(); ++i) {
     ModelSafeWorker* worker = session->workers()[i];
     ModelSafeGroup group = worker->GetModelSafeGroup();
     // Skip workers whose group isn't active.
     if (active_groups.find(group) == active_groups.end()) {
       VLOG(2) << "Skipping worker for group "
               << ModelSafeGroupToString(group);
       continue;
     }
 
-    sessions::StatusController* status = work_session_->status_controller();
+    sessions::StatusController* status =
+        work_session_->mutable_status_controller();
     sessions::ScopedModelSafeGroupRestriction r(status, group);
     WorkCallback c = base::Bind(
         &ModelChangingSyncerCommand::StartChangingModel,
         // 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