Omnibox: Create Field Trial for HQP to Ignore Mid-Word Matches

chrome/browser/history/scored_history_match.h

Index: chrome/browser/history/scored_history_match.h
diff --git a/chrome/browser/history/scored_history_match.h b/chrome/browser/history/scored_history_match.h
index c10f4f3b70d881f3c5dc81cd1d5b95c685ca436b..60ee92d5541a305d097fa445eda37487a0f69c81 100644
--- a/chrome/browser/history/scored_history_match.h
+++ b/chrome/browser/history/scored_history_match.h
@@ -38,12 +38,22 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
                      BookmarkService* bookmark_service);
   ~ScoredHistoryMatch();
 
-  // Calculates a component score based on position, ordering and total
-  // substring match size using metrics recorded in |matches|. |max_length|
-  // is the length of the string against which the terms are being searched.
+  // Calculates a component score based on position, ordering, word
+  // boundaries, and total substring match size using metrics recorded
+  // in |matches| and |word_starts|. |max_length| is the length of
+  // the string against which the terms are being searched.
   static int ScoreComponentForMatches(const TermMatches& matches,

[Bart N., 2012/11/29 17:32:26]

matches -> provided_matches to make it consistent with your implementation.

[Mark P, 2012/11/29 19:36:48]

Done.

+                                      const WordStarts& word_starts,
                                       size_t max_length);
 
+  // Given a set of term matches |matches| and word boundaries |word_starts|,
+  // fills in |matches_at_word_boundaries| with only the matches in |matches|
+  // that are at word boundaries.
+  static void MakeTermMatchesOnlyAtWordBoundaries(
+      const TermMatches& matches,
+      const WordStarts& word_starts,
+      TermMatches* matches_at_word_boundaries);
+
   // Converts a raw value for some particular scoring factor into a score
   // component for that factor.  The conversion function is piecewise linear,
   // with input values provided in |value_ranks| and resulting output scores
@@ -102,6 +112,9 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
   // field trial state.
   static void InitializeNewScoringField();
 
+  // Sets only_count_matches_at_word_boundaries based on the field trial state.
+  static void InitializeOnlyCountMatchesAtWordBoundariesField();
+
   // Sets also_do_hup_like_scoring based on the field trial state.
   static void InitializeAlsoDoHUPLikeScoringField();
 
@@ -134,7 +147,8 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
   static const int kMaxRawTermScore = 30;
   static float* raw_term_score_to_topicality_score;
 
-  // Allows us to determing setting for use_new_scoring_ only once.
+  // Allows us to determing setting for use_new_scoring_ and other startup

[Bart N., 2012/11/29 17:32:26]

-> |use_new_scoring| (extra _)?

[Mark P, 2012/11/29 19:36:48]

Rephrased entirely.

+  // calculations only once.
   static bool initialized_;
 
   // Whether to use new-scoring or old-scoring.  Set in the
@@ -145,6 +159,9 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
   // class as well (see boolean below).
   static bool use_new_scoring;
 
+  // If true, we ignore all matches that are in the middle of a word.
+  static bool only_count_matches_at_word_boundaries;
+
   // If true, assign raw scores to be max(whatever it normally would be,
   // a score that's similar to the score HistoryURL provider would assign).
   // This variable is set in the constructor by examining the field trial