Make HistoryDBTask not refcounted, and ensure it's destroyed on its origin 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 f49b30868356923706d77f2081808c22a715562b..b4bb3eb9ac77edb7cd694546615079b6af140666 100644
--- a/chrome/browser/sync/profile_sync_service_typed_url_unittest.cc
+++ b/chrome/browser/sync/profile_sync_service_typed_url_unittest.cc
@@ -114,7 +114,7 @@ class HistoryServiceMock : public HistoryService {
   explicit HistoryServiceMock(history::HistoryClient* client, Profile* profile)
       : HistoryService(client, profile) {}
   MOCK_METHOD2(ScheduleDBTask,
-               void(scoped_refptr<history::HistoryDBTask>,
+               void(history::HistoryDBTask*,
                     base::CancelableTaskTracker*));
   MOCK_METHOD0(Shutdown, void());
 
@@ -152,14 +152,15 @@ class TestTypedUrlModelAssociator : public TypedUrlModelAssociator {
 };
 
 void RunOnDBThreadCallback(HistoryBackend* backend,
-                           scoped_refptr<history::HistoryDBTask> task) {
+                           scoped_ptr<history::HistoryDBTask> task) {
   task->RunOnDBThread(backend, NULL);
 }
 
 ACTION_P2(RunTaskOnDBThread, thread, backend) {
   thread->message_loop()->PostTask(
       FROM_HERE,
-      base::Bind(&RunOnDBThreadCallback, base::Unretained(backend), arg0));
+      base::Bind(&RunOnDBThreadCallback, base::Unretained(backend),
+                 base::Passed(make_scoped_ptr(arg0))));
 }
 
 ACTION_P2(ShutdownHistoryService, thread, service) {