Omnibox - Boost Frequency Scores Based on Number of Matching Pages

components/omnibox/browser/scored_history_match.h

Index: components/omnibox/browser/scored_history_match.h
diff --git a/components/omnibox/browser/scored_history_match.h b/components/omnibox/browser/scored_history_match.h
index dacd31cec537b30c501c35a6410bca55cbe20d96..dd6c36a9f1ef9dd877e438075da2822adb5561b2 100644
--- a/components/omnibox/browser/scored_history_match.h
+++ b/components/omnibox/browser/scored_history_match.h
@@ -16,6 +16,7 @@
 #include "components/history/core/browser/history_match.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/omnibox/browser/in_memory_url_index_types.h"
+#include "components/omnibox/browser/omnibox_field_trial.h"
 
 class ScoredHistoryMatchTest;
 
@@ -43,9 +44,11 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
   // These offsets (".net" should have an offset of 1) come from
   // |terms_to_word_starts_offsets|. |is_url_bookmarked| indicates whether the
   // match's URL is referenced by any bookmarks, which can also affect the raw
-  // score.  The raw score allows the matches to be ordered and can be used to
-  // influence the final score calculated by the client of this index.  If the
-  // row does not qualify the raw score will be 0.
+  // score.  |num_matching_pages| indicates how many URLs in the eligible URL
+  // database match the user's input; it can also affect the raw score.  The raw
+  // score allows the matches to be ordered and can be used to influence the
+  // final score calculated by the client of this index.  If the row does not
+  // qualify the raw score will be 0.
   ScoredHistoryMatch(const history::URLRow& row,
                      const VisitInfoVector& visits,
                      const base::string16& lower_string,
@@ -53,6 +56,7 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
                      const WordStarts& terms_to_word_starts_offsets,
                      const RowWordStarts& word_starts,
                      bool is_url_bookmarked,
+                     size_t num_matching_pages,
                      base::Time now);
 
   ~ScoredHistoryMatch();
@@ -93,6 +97,7 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
 
  private:
   friend class ScoredHistoryMatchTest;
+  FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, GetDocumentSpecificityScore);
   FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, GetFinalRelevancyScore);
   FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, GetFrequency);
   FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, GetHQPBucketsFromString);
@@ -128,13 +133,18 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
                      const bool bookmarked,
                      const VisitInfoVector& visits) const;
 
-  // Combines the two component scores into a final score that's
+  // Returns a document specificity score based on how many pages matched the
+  // user's input.
+  float GetDocumentSpecificityScore(size_t num_matching_pages) const;
+
+  // Combines the three component scores into a final score that's
   // an appropriate value to use as a relevancy score. Scoring buckets are
   // specified through |hqp_relevance_buckets|. Please see the function
   // implementation for more details.
   static float GetFinalRelevancyScore(
       float topicality_score,
       float frequency_score,
+      float specificity_score,
       const std::vector<ScoreMaxRelevance>& hqp_relevance_buckets);
 
   // Initializes the HQP experimental params: |hqp_relevance_buckets_|
@@ -200,6 +210,12 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
   // to the final relevance scoring. Please see GetFinalRelevancyScore()
   // for more details and scoring method.
   static std::vector<ScoreMaxRelevance>* hqp_relevance_buckets_;
+
+  // Used for testing.  If this point is not null, it overrides the static

[Peter Kasting, 2016/12/10 02:22:26]

Nit: pointer

[Mark P, 2016/12/11 05:11:37]

Done.

+  // local variable |default_num_matches_to_document_specificity_score|
+  // declared in GetDocumentSpecificityScore().
+  static OmniboxFieldTrial::NumMatchesScores*
+      num_matches_to_document_specificity_score_override_;
 };
 typedef std::vector<ScoredHistoryMatch> ScoredHistoryMatches;