Replace refcounting with weak pointers for BookmarkStore.

components/bookmarks/browser/bookmark_storage.h

 // Copyright 2014 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_BOOKMARKS_BROWSER_BOOKMARK_STORAGE_H_
 #define COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_STORAGE_H_
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "base/files/important_file_writer.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
 #include "components/bookmarks/browser/bookmark_node.h"
 
 class BookmarkModel;
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace bookmarks {
 
@@ skipping 102 matching lines @@
   bool ids_reassigned_;
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkLoadDetails);
 };
 
 // BookmarkStorage handles reading/write the bookmark bar model. The
 // BookmarkModel uses the BookmarkStorage to load bookmarks from disk, as well
 // as notifying the BookmarkStorage every time the model changes.
 //
 // Internally BookmarkStorage uses BookmarkCodec to do the actual read/write.
-class BookmarkStorage : public base::ImportantFileWriter::DataSerializer,
-                        public base::RefCountedThreadSafe<BookmarkStorage> {
+class BookmarkStorage : public base::ImportantFileWriter::DataSerializer {
  public:
   // Creates a BookmarkStorage for the specified model. The data will be loaded
   // from and saved to a location derived from |profile_path|. The IO code will
   // be executed as a task in |sequenced_task_runner|.
   BookmarkStorage(BookmarkModel* model,
                   const base::FilePath& profile_path,
                   base::SequencedTaskRunner* sequenced_task_runner);
+  virtual ~BookmarkStorage();
 
   // Loads the bookmarks into the model, notifying the model when done. This
   // takes ownership of |details| and send the |OnLoadFinished| callback from
   // a task in |task_runner|. See BookmarkLoadDetails for details.
   void LoadBookmarks(
       scoped_ptr<BookmarkLoadDetails> details,
       const scoped_refptr<base::SequencedTaskRunner>& task_runner);
 
   // Schedules saving the bookmark bar model to disk.
   void ScheduleSave();
 
   // Notification the bookmark bar model is going to be deleted. If there is
   // a pending save, it is saved immediately.
   void BookmarkModelDeleted();
 
   // Callback from backend after loading the bookmark file.
   void OnLoadFinished();
 
   // ImportantFileWriter::DataSerializer implementation.
   virtual bool SerializeData(std::string* output) OVERRIDE;
 
  private:
-  friend class base::RefCountedThreadSafe<BookmarkStorage>;
-
-  virtual ~BookmarkStorage();
-
   // Serializes the data and schedules save using ImportantFileWriter.
   // Returns true on successful serialization.
   bool SaveNow();
 
   // The model. The model is NULL once BookmarkModelDeleted has been invoked.
   BookmarkModel* model_;
 
   // Helper to write bookmark data safely.
   base::ImportantFileWriter writer_;
 
   // See class description of BookmarkLoadDetails for details on this.
   scoped_ptr<BookmarkLoadDetails> details_;
 
   // Sequenced task runner where file I/O operations will be performed at.
   scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner_;
 
+  base::WeakPtrFactory<BookmarkStorage> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(BookmarkStorage);
 };
 
 }  // namespace bookmarks
 
 #endif  // COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_STORAGE_H_