Only wait for CancelAllRequests done if the post task succeeds

chrome/browser/history/android/sqlite_cursor.h

Index: chrome/browser/history/android/sqlite_cursor.h
diff --git a/chrome/browser/history/android/sqlite_cursor.h b/chrome/browser/history/android/sqlite_cursor.h
index ebd6213b597f3d3791341c8df8e8070727190390..2da09f7e34ed853b464682753d436c9406716f9a 100644
--- a/chrome/browser/history/android/sqlite_cursor.h
+++ b/chrome/browser/history/android/sqlite_cursor.h
@@ -136,6 +136,10 @@ class SQLiteCursor {
 
   virtual ~SQLiteCursor();
 
+  // Destory SQLiteCursor object on UI thread. All cleanup need finish in UI
+  // thread.
+  void DestroyOnUIThread();
+
   // This method is for testing only.
   void set_test_observer(TestObserver* test_observer) {
     test_observer_ = test_observer;
@@ -155,9 +159,6 @@ class SQLiteCursor {
   // The callback function of MoveTo().
   void OnMoved(AndroidHistoryProviderService::Handle handle, int pos);
 
-  // Used to cancel all request on the UI thread during shutdown.
-  void CancelAllRequests(base::WaitableEvent* finished);
-
   JavaColumnType GetColumnTypeInternal(int column);
 
   // Runs the MoveStatement on UI thread.