Remove some uses of stl_util's STLDeleteContainerPointers.

components/history/core/browser/history_backend.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 853 matching lines @@
   base::Closure backend_destroy_task_;
 
   // Tracks page transition types.
   VisitTracker tracker_;
 
   // A boolean variable to track whether we have already purged obsolete segment
   // data.
   bool segment_queried_;
 
   // List of QueuedHistoryDBTasks to run;
-  std::list<QueuedHistoryDBTask*> queued_history_db_tasks_;
+  std::list<std::unique_ptr<QueuedHistoryDBTask>> queued_history_db_tasks_;
 
   // Used to determine if a URL is bookmarked; may be null.
   std::unique_ptr<HistoryBackendClient> backend_client_;
 
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
 
   // Used to allow embedder code to stash random data by key. Those object will
   // be deleted before closing the databases (hence the member variable instead
   // of inheritance from base::SupportsUserData).
   std::unique_ptr<HistoryBackendHelper> supports_user_data_helper_;
@@ skipping 15 matching lines @@
 
   // List of observers
   base::ObserverList<HistoryBackendObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_