flat containers prototype

components/omnibox/browser/url_index_private_data.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_OMNIBOX_BROWSER_URL_INDEX_PRIVATE_DATA_H_
 #define COMPONENTS_OMNIBOX_BROWSER_URL_INDEX_PRIVATE_DATA_H_
 
 #include <stddef.h>
 
 #include <set>
@@ skipping 169 matching lines @@
     // Creates a cache item for a term which has no results.
     SearchTermCacheItem();
     SearchTermCacheItem(const SearchTermCacheItem& other);
 
     ~SearchTermCacheItem();
 
     WordIDSet word_id_set_;
     HistoryIDSet history_id_set_;
     bool used_;  // True if this item has been used for the current term search.
   };
-  typedef std::map<base::string16, SearchTermCacheItem> SearchTermCacheMap;
+  typedef base::flat_map<base::string16, SearchTermCacheItem>
+      SearchTermCacheMap;
 
   // A helper predicate class used to filter excess history items when the
   // candidate results set is too large.
   class HistoryItemFactorGreater {
    public:
     explicit HistoryItemFactorGreater(const HistoryInfoMap& history_info_map);
     ~HistoryItemFactorGreater();
 
     bool operator()(const HistoryID h1, const HistoryID h2);
 
@@ skipping 180 matching lines @@
   int saved_cache_version_;
 
   // Used for unit testing only. Records the number of candidate history items
   // at three stages in the index searching process.
   size_t pre_filter_item_count_;    // After word index is queried.
   size_t post_filter_item_count_;   // After trimming large result set.
   size_t post_scoring_item_count_;  // After performing final filter/scoring.
 };
 
 #endif  // COMPONENTS_OMNIBOX_BROWSER_URL_INDEX_PRIVATE_DATA_H_