sync: Add pre-commit update avoidance mode + flag

sync/internal_api/test/test_internal_components_factory.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.
 
 #include "sync/internal_api/public/test/test_internal_components_factory.h"
 
 #include "sync/sessions/sync_session_context.h"
 #include "sync/syncable/in_memory_directory_backing_store.h"
 #include "sync/syncable/on_disk_directory_backing_store.h"
 #include "sync/syncable/invalid_directory_backing_store.h"
@@ skipping 27 matching lines @@
     const std::string& invalidator_client_id) {
 
   // Tests don't wire up listeners.
   std::vector<SyncEngineEventListener*> empty_listeners;
   return scoped_ptr<sessions::SyncSessionContext>(
       new sessions::SyncSessionContext(
           connection_manager, directory, workers, monitor,
           empty_listeners, debug_info_getter,
           traffic_recorder,
           switches_.encryption_method == ENCRYPTION_KEYSTORE,
+          switches_.pre_commit_updates_policy ==
+              FORCE_ENABLE_PRE_COMMIT_UPDATE_AVOIDANCE,
           invalidator_client_id));
 
 }
 
 scoped_ptr<syncable::DirectoryBackingStore>
 TestInternalComponentsFactory::BuildDirectoryBackingStore(
       const std::string& dir_name, const base::FilePath& backing_filepath) {
   switch (storage_option_) {
     case STORAGE_IN_MEMORY:
       return scoped_ptr<syncable::DirectoryBackingStore>(
           new syncable::InMemoryDirectoryBackingStore(dir_name));
     case STORAGE_ON_DISK:
       return scoped_ptr<syncable::DirectoryBackingStore>(
           new syncable::OnDiskDirectoryBackingStore(dir_name,
                                                     backing_filepath));
     case STORAGE_INVALID:
       return scoped_ptr<syncable::DirectoryBackingStore>(
           new syncable::InvalidDirectoryBackingStore());
   }
   NOTREACHED();
   return scoped_ptr<syncable::DirectoryBackingStore>();
 }
 
 InternalComponentsFactory::Switches
 TestInternalComponentsFactory::GetSwitches() const {
   return switches_;
 }
 
 }  // namespace syncer