[Sync] Split DirectoryChangeListener for thread-safety

chrome/browser/sync/engine/build_and_process_conflict_sets_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/build_and_process_conflict_sets_command.h"
 
 #include <set>
 #include <string>
 #include <sstream>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/format_macros.h"
+#include "base/tracked.h"
 #include "chrome/browser/sync/engine/syncer_util.h"
 #include "chrome/browser/sync/engine/update_applicator.h"
 #include "chrome/browser/sync/sessions/sync_session.h"
 #include "chrome/browser/sync/syncable/directory_manager.h"
 
 namespace browser_sync {
 
 using sessions::ConflictProgress;
 using sessions::StatusController;
 using sessions::SyncSession;
@@ skipping 12 matching lines @@
 }
 
 bool BuildAndProcessConflictSetsCommand::BuildAndProcessConflictSets(
     SyncSession* session) {
   syncable::ScopedDirLookup dir(session->context()->directory_manager(),
                                 session->context()->account_name());
   if (!dir.good())
     return false;
   bool had_single_direction_sets = false;
   {  // Scope for transaction.
-    syncable::WriteTransaction trans(dir, syncable::SYNCER, __FILE__, __LINE__);
+    syncable::WriteTransaction trans(dir, syncable::SYNCER, FROM_HERE);
     BuildConflictSets(&trans,
         session->status_controller()->mutable_conflict_progress());
     had_single_direction_sets = ProcessSingleDirectionConflictSets(&trans,
         session->context()->resolver(),
         session->context()->directory_manager()->GetCryptographer(&trans),
         session->status_controller(), session->routing_info());
     // We applied some updates transactionally, lets try syncing again.
     if (had_single_direction_sets)
       return true;
   }
@@ skipping 342 matching lines @@
     LocallyDeletedPathChecker checker;
     if (!checker.CausingConflict(parent, *entry))
       return;
     conflict_progress->MergeSets(entry->Get(syncable::ID),
                                  parent.Get(syncable::ID));
     CrawlDeletedTreeMergingSets(trans, parent, conflict_progress, checker);
   }
 }
 
 }  // namespace browser_sync