Optimizing HQP using vectors manually. This is just a CL to be able

components/omnibox/browser/url_index_private_data.h

Index: components/omnibox/browser/url_index_private_data.h
diff --git a/components/omnibox/browser/url_index_private_data.h b/components/omnibox/browser/url_index_private_data.h
index 100692cd7b44e63de9bfbc2b01c3501a6e2bbd95..a3f1c4a3dab70f4df6b431fde272b4d8c13782f2 100644
--- a/components/omnibox/browser/url_index_private_data.h
+++ b/components/omnibox/browser/url_index_private_data.h
@@ -172,16 +172,15 @@ class URLIndexPrivateData
   // characters in the prefix by returning the |word_id_set|. In that case we do
   // not mark the item as being |used_|.
   struct SearchTermCacheItem {
-    SearchTermCacheItem(const WordIDSet& word_id_set,
-                        const HistoryIDSet& history_id_set);
+    SearchTermCacheItem(WordIDVector word_id_set, HistoryIDVector history_ids);
     // 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_;
+    WordIDVector word_id_set_;
+    HistoryIDVector history_id_set_;
     bool used_;  // True if this item has been used for the current term search.
   };
   typedef std::map<base::string16, SearchTermCacheItem> SearchTermCacheMap;
@@ -237,10 +236,10 @@ class URLIndexPrivateData
 
   // Helper function to HistoryIDSetFromWords which composes a set of history
   // ids for the given term given in |term|.
-  HistoryIDSet HistoryIDsForTerm(const base::string16& term);
+  HistoryIDVector HistoryIDsForTerm(const base::string16& term);
 
   // Given a set of Char16s, finds words containing those characters.
-  WordIDSet WordIDSetForTermChars(const Char16Set& term_chars);
+  WordIDVector WordIDSetForTermChars(const Char16Set& term_chars);
 
   // Indexes one URL history item as described by |row|. Returns true if the
   // row was actually indexed. |scheme_whitelist| is used to filter