Port HistoryService::ScheduleDBTask to CancelableTaskTracker

chrome/browser/history/delete_directive_handler.h

Index: chrome/browser/history/delete_directive_handler.h
diff --git a/chrome/browser/history/delete_directive_handler.h b/chrome/browser/history/delete_directive_handler.h
index 70992a0b933b53f8d1b12bc042452f15fd1bd8f5..31ed47ee0ae5966565bdda2263c8081dfd3ff5fb 100644
--- a/chrome/browser/history/delete_directive_handler.h
+++ b/chrome/browser/history/delete_directive_handler.h
@@ -7,8 +7,8 @@
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/task/cancelable_task_tracker.h"
 #include "base/threading/thread_checker.h"
-#include "chrome/browser/common/cancelable_request.h"
 #include "sync/api/sync_change_processor.h"
 #include "sync/api/sync_data.h"
 
@@ -71,7 +71,7 @@ class DeleteDirectiveHandler {
   void FinishProcessing(PostProcessingAction post_processing_action,
                         const syncer::SyncDataList& delete_directives);
 
-  CancelableRequestConsumer internal_consumer_;
+  base::CancelableTaskTracker internal_tracker_;
   scoped_ptr<syncer::SyncChangeProcessor> sync_processor_;
   base::ThreadChecker thread_checker_;
   base::WeakPtrFactory<DeleteDirectiveHandler> weak_ptr_factory_;