[AiS] Use top local result for prefetch.

components/omnibox/search_provider.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.
 //
 // This file contains the Search autocomplete provider.  This provider is
 // responsible for all autocomplete entries that start with "Search <engine>
 // for ...", including searching for the current input string, search
 // history, and search suggestions.  An instance of it gets created and
 // managed by the autocomplete controller.
 
@@ skipping 228 matching lines @@
   // See UpdateMatches() for the use and explanation of this constraint
   // and other constraints enforced without the use of helper functions.
   bool IsTopMatchSearchWithURLInput() const;
 
   // Converts an appropriate number of navigation results in
   // |navigation_results| to matches and adds them to |matches|.
   void AddNavigationResultsToMatches(
       const SearchSuggestionParser::NavigationResults& navigation_results,
       ACMatches* matches);
 
   // Adds a match for each result in |results| to |map|. |is_keyword| indicates

[Mark P, 2014/09/25 22:36:45]

nit: please revise this comment so as not to reference |results|

[groby-ooo-7-16, 2014/09/26 00:20:42]

Done.

   // whether the results correspond to the keyword provider or default provider.
-  void AddHistoryResultsToMap(const HistoryResults& results,
-                              bool is_keyword,
-                              int did_not_accept_suggestion,
-                              MatchMap* map);
+  void AddRawHistoryResultsToMap(bool is_keyword,
+                                 int did_not_accept_suggestion,
+                                 MatchMap* map);
+
+  // Adds a match for each transformed result in |results| to |map|.
+  void AddTransformedHistoryResultsToMap(
+      const SearchSuggestionParser::SuggestResults& results,
+      int did_not_accept_suggestion,
+      MatchMap* map);
 
   // Calculates relevance scores for all |results|.
-  SearchSuggestionParser::SuggestResults ScoreHistoryResults(
+  SearchSuggestionParser::SuggestResults ScoreHistoryResultsHelper(
       const HistoryResults& results,
       bool base_prevent_inline_autocomplete,
       bool input_multiple_words,
       const base::string16& input_text,
       bool is_keyword);
 
+  // Calculates relevance scores for |results|, adjusting for boundary
+  // conditions around multi-word queries. (See inline comments in function
+  // definition for more details.)
+  void ScoreHistoryResults(
+      const HistoryResults& results,
+      bool is_keyword,
+      SearchSuggestionParser::SuggestResults* scored_results);
+
   // Adds matches for |results| to |map|.
   void AddSuggestResultsToMap(
       const SearchSuggestionParser::SuggestResults& results,
       const std::string& metadata,
       MatchMap* map);
 
   // Gets the relevance score for the verbatim result.  This value may be
   // provided by the suggest server or calculated locally; if
   // |relevance_from_server| is non-NULL, it will be set to indicate which of
   // those is true.
@@ skipping 32 matching lines @@
   // Returns an AutocompleteMatch for a navigational suggestion.
   AutocompleteMatch NavigationToMatch(
       const SearchSuggestionParser::NavigationResult& navigation);
 
   // Updates the value of |done_| from the internal state.
   void UpdateDone();
 
   // Obtains a session token, regenerating if necessary.
   std::string GetSessionToken();
 
-  // Answers prefetch handling - finds previously displayed answer matching the
-  // current |input| and sets |prefetch_data_|.
-  void DoAnswersQuery(const AutocompleteInput& input);
+  // Answers prefetch handling - finds the previously displayed answer matching
+  // the current top-scoring history result. If there is a previous answer,
+  // returns the query data associated with it. Otherwise, returns an empty
+  // AnswersQueryData.
+  AnswersQueryData FindAnswersPrefetchData();
 
   // The amount of time to wait before sending a new suggest request after the
   // previous one.  Non-const because some unittests modify this value.
   static int kMinimumTimeBetweenSuggestQueriesMs;
 
   AutocompleteProviderListener* listener_;
 
   // The number of suggest results that haven't yet arrived. If it's greater
   // than 0, it indicates that one of the URLFetchers is still running.
   int suggest_results_pending_;
 
   // Maintains the TemplateURLs used.
   Providers providers_;
 
   // The user's input.
   AutocompleteInput input_;
 
   // Input when searching against the keyword provider.
   AutocompleteInput keyword_input_;
 
   // Searches in the user's history that begin with the input text.
-  HistoryResults keyword_history_results_;
-  HistoryResults default_history_results_;
+  HistoryResults raw_keyword_history_results_;
+  HistoryResults raw_default_history_results_;
+
+  // Scored searches in the user's history - based on |keyword_history_results_|
+  // or |default_history_results_| as appropriate.
+  SearchSuggestionParser::SuggestResults transformed_keyword_history_results_;
+  SearchSuggestionParser::SuggestResults transformed_default_history_results_;
 
   // A timer to start a query to the suggest server after the user has stopped
   // typing for long enough.
   base::OneShotTimer<SearchProvider> timer_;
 
   // The time at which we sent a query to the suggest server.
   base::TimeTicks time_suggest_request_sent_;
 
   // Fetchers used to retrieve results for the keyword and default providers.
   scoped_ptr<net::URLFetcher> keyword_fetcher_;
@@ skipping 15 matching lines @@
   base::TimeTicks token_expiration_time_;
 
   // Answers prefetch management.
   AnswersCache answers_cache_;  // Cache for last answers seen.
   AnswersQueryData prefetch_data_;  // Data to use for query prefetching.
 
   DISALLOW_COPY_AND_ASSIGN(SearchProvider);
 };
 
 #endif  // COMPONENTS_OMNIBOX_SEARCH_PROVIDER_H_