Factor out bookmark-specific sorting logic from BookmarkIndex

components/bookmarks/browser/bookmark_index.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_INDEX_H_
 #define COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_INDEX_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "components/query_parser/query_parser.h"
 
 namespace bookmarks {
 
-class BookmarkClient;
 class TitledUrlNode;
+class TitledUrlNodeSorter;
 struct BookmarkMatch;
 
 // BookmarkIndex maintains an index of the titles and URLs of bookmarks for
 // quick look up. BookmarkIndex is owned and maintained by BookmarkModel, you
 // shouldn't need to interact directly with BookmarkIndex.
 //
 // BookmarkIndex maintains the index (index_) as a map of sets. The map (type
 // Index) maps from a lower case string to the set (type NodeSet) of
 // TitledUrlNodes that contain that string in their title or URL.
 class BookmarkIndex {
  public:
-  BookmarkIndex(BookmarkClient* client);
+  BookmarkIndex(std::unique_ptr<TitledUrlNodeSorter> sorter);
   ~BookmarkIndex();
 
   // Invoked when a title/URL pair has been added to the model.
   void Add(const TitledUrlNode* node);
 
   // Invoked when a title/URL pair has been removed from the model.
   void Remove(const TitledUrlNode* node);
 
   // Returns up to |max_count| of matches containing each term from the text
   // |query| in either the title or the URL.
@@ skipping 32 matching lines @@
   std::vector<base::string16> ExtractQueryWords(const base::string16& query);
 
   // Adds |node| to |index_|.
   void RegisterNode(const base::string16& term, const TitledUrlNode* node);
 
   // Removes |node| from |index_|.
   void UnregisterNode(const base::string16& term, const TitledUrlNode* node);
 
   Index index_;
 
-  BookmarkClient* const client_;
+  std::unique_ptr<TitledUrlNodeSorter> sorter_;
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkIndex);
 };
 
 }  // namespace bookmarks
 
 #endif  // COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_INDEX_H_