[Sync] Consolidate DataTypeController methods that post on the backend thread

chrome/browser/sync/profile_sync_service_typed_url_unittest.cc

Index: chrome/browser/sync/profile_sync_service_typed_url_unittest.cc
diff --git a/chrome/browser/sync/profile_sync_service_typed_url_unittest.cc b/chrome/browser/sync/profile_sync_service_typed_url_unittest.cc
index fd0ac0abfff354ca1c835fb9cae9edfeeb51711b..7629c6f9ebf71ffebea026e659ce229ced1317be 100644
--- a/chrome/browser/sync/profile_sync_service_typed_url_unittest.cc
+++ b/chrome/browser/sync/profile_sync_service_typed_url_unittest.cc
@@ -119,9 +119,12 @@ void RunOnDBThreadCallback(HistoryBackend* backend,
 }
 
 ACTION_P2(RunTaskOnDBThread, thread, backend) {
- thread->message_loop()->PostTask(
-    FROM_HERE, base::Bind(&RunOnDBThreadCallback, base::Unretained(backend),
-                          base::Unretained(arg0)));
+  // ScheduleDBTask takes ownership of its task argument, so we
+  // should, too.
+  scoped_refptr<HistoryDBTask> task(arg0);
+  thread->message_loop()->PostTask(
+      FROM_HERE, base::Bind(&RunOnDBThreadCallback, base::Unretained(backend),
+                            task));
 }
 
 ACTION_P4(MakeTypedUrlSyncComponents, profile, service, hb, dtc) {