[SyncFS] Clear dirty flag on changelist application phase

chrome/browser/sync_file_system/drive_backend/list_changes_task.cc

Index: chrome/browser/sync_file_system/drive_backend/list_changes_task.cc
diff --git a/chrome/browser/sync_file_system/drive_backend/list_changes_task.cc b/chrome/browser/sync_file_system/drive_backend/list_changes_task.cc
index 01cb0fbc40e8bf55067a9fcec5bf2e60214ae38a..7732db22551f0317100178567c9900ff19f302e2 100644
--- a/chrome/browser/sync_file_system/drive_backend/list_changes_task.cc
+++ b/chrome/browser/sync_file_system/drive_backend/list_changes_task.cc
@@ -116,6 +116,18 @@ void ListChangesTask::CheckInChangeList(int64 largest_change_id,
   metadata_database()->UpdateByChangeList(
       largest_change_id,
       change_list_.Pass(),
+      base::Bind(&ListChangesTask::DidCheckInChangeList,
+                 weak_ptr_factory_.GetWeakPtr(), base::Passed(&token)));
+}
+
+void ListChangesTask::DidCheckInChangeList(scoped_ptr<SyncTaskToken> token,
+                                           SyncStatusCode status) {
+  if (status != SYNC_STATUS_OK) {
+    SyncTaskManager::NotifyTaskDone(token.Pass(), status);
+    return;
+  }
+
+  metadata_database()->SweepDirtyTrackers(
       base::Bind(&SyncTaskManager::NotifyTaskDone, base::Passed(&token)));
 }