Replace refcounting with weak pointers for BookmarkStore.

components/bookmarks/browser/bookmark_model.cc

 // 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.
 
 #include "components/bookmarks/browser/bookmark_model.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/bind.h"
@@ skipping 129 matching lines @@
     // If the store is non-null, it means Load was already invoked. Load should
     // only be invoked once.
     NOTREACHED();
     return;
   }
 
   expanded_state_tracker_.reset(
       new BookmarkExpandedStateTracker(this, pref_service));
 
   // Load the bookmarks. BookmarkStorage notifies us when done.
-  store_ = new BookmarkStorage(this, profile_path, io_task_runner.get());
+  store_ .reset(new BookmarkStorage(this, profile_path, io_task_runner.get()));
   store_->LoadBookmarks(CreateLoadDetails(accept_languages), ui_task_runner);
 }
 
 const BookmarkNode* BookmarkModel::GetParentForNewNodes() {
   std::vector<const BookmarkNode*> nodes =
       bookmark_utils::GetMostRecentlyModifiedUserFolders(this, 1);
   DCHECK(!nodes.empty());  // This list is always padded with default folders.
   return nodes[0];
 }
 
@@ skipping 532 matching lines @@
     const base::string16& text,
     size_t max_count,
     std::vector<BookmarkMatch>* matches) {
   if (!loaded_)
     return;
 
   index_->GetBookmarksMatching(text, max_count, matches);
 }
 
 void BookmarkModel::ClearStore() {
-  store_ = NULL;
+  store_.reset();
 }
 
 void BookmarkModel::SetPermanentNodeVisible(BookmarkNode::Type type,
                                             bool value) {
   BookmarkPermanentNode* node = AsMutable(PermanentNode(type));
   node->set_visible(value || client_->IsPermanentNodeVisible(node));
 }
 
 const BookmarkPermanentNode* BookmarkModel::PermanentNode(
     BookmarkNode::Type type) {
@@ skipping 293 matching lines @@
   BookmarkPermanentNode* mobile_node =
       CreatePermanentNode(BookmarkNode::MOBILE);
   return scoped_ptr<BookmarkLoadDetails>(new BookmarkLoadDetails(
       bb_node,
       other_node,
       mobile_node,
       client_->GetLoadExtraNodesCallback(),
       new BookmarkIndex(client_, index_urls_, accept_languages),
       next_node_id_));
 }