Adding knobs on HQP provider.

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 15a37e7bd73673dc4efe2ca93a5e29a06d3e8d59..5ffa73c4caf5d786f9485a110bf570240c2999da 100644
--- a/chrome/browser/history/scored_history_match.h
+++ b/chrome/browser/history/scored_history_match.h
@@ -29,6 +29,11 @@ class ScoredHistoryMatch : public history::HistoryMatch {
   // expected to deliver (at minimum) to this class.
   static const size_t kMaxVisitsToScore;
 
+  // ScoreMaxRelevance maps from intermediate-score to the final-relevance

[Mark P, 2015/02/14 01:27:14]

from -> from an
to the -> to the maximum

[Ashok vardhan, 2015/02/17 01:23:53]

Done.

+  // score given to URL. This is used to store the score ranges of HQP relevance

[Mark P, 2015/02/14 01:27:14]

to URL -> to a URL for this intermediate score.

[Ashok vardhan, 2015/02/17 01:23:53]

Done.

+  // buckets. Please see GetFinalRelevancyScore() for details.
+  typedef std::pair<double, int> ScoreMaxRelevance;
+
   ScoredHistoryMatch();  // Required by STL.
 
   // Creates a new match with a raw score calculated for the history item
@@ -83,6 +88,7 @@ class ScoredHistoryMatch : public history::HistoryMatch {
 
  private:
   friend class ScoredHistoryMatchTest;
+  FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, GetFinalRelevancyScore);
   FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringBookmarks);
   FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringDiscountFrecency);
   FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringScheme);
@@ -127,10 +133,34 @@ class ScoredHistoryMatch : public history::HistoryMatch {
                             const VisitInfoVector& visits);
 
   // Combines the two component scores into a final score that's
-  // an appropriate value to use as a relevancy score.
+  // an appropriate value to use as a relevancy score. Scoring buckets are
+  // specified through |hqp_relevance_buckets|. Please see function

[Mark P, 2015/02/14 01:27:14]

see -> see the

[Ashok vardhan, 2015/02/17 01:23:52]

Done.

+  // implementation for more details.
   static float GetFinalRelevancyScore(
       float topicality_score,
-      float frequency_score);
+      float frequency_score,
+      const std::vector<ScoreMaxRelevance>& hqp_relevance_buckets);
+
+  // Initializes the HQP experimental params.

[Mark P, 2015/02/14 01:27:14]

This comment is a verb, implying it should go next to a function.  Yet it's
associated with a variable.  Please rearrange/revise these comments so they're
appropriate.

Also note that the style guide says all functions should be declared in class
files before all variables.

[Ashok vardhan, 2015/02/17 01:23:53]

Done.

+  // If the experimental scoring is enabled, it sets:

[Mark P, 2015/02/14 01:27:14]

By the way, this comment is wrong as written.  In particular, you end up seeing
some of these variables even if hqp_experimental_scoring is not enabled (and you
rely on these settings in the code even when experimental scoring is not
enabled).

+  //
+  // 1. hqp_experimental to true. Default value is set to false.
+  //
+  // 2. It initializes the topicality_threshold_, and hqp_scoring from the
+  //    finch experiment params.
+  //
+  // 3. topicality_threshold_ is used to control the topicality scoring.
+  // If topicality_threshold > 0, then URLs with topicality score < threshold,
+  // are given score 0. It is initalized to -1;
+  //
+  // 4. hqp_relevance_buckets_, buckets that gives the mapping from
+  // (topicality*frequency) to the final relevance scoring.
+  // Please see GetFinalRelevancyScore() for more details and scoring method.
+  static bool hqp_experimental_scoring_enabled_;
+  static float topicality_threshold_;
+  static std::vector<ScoreMaxRelevance>* hqp_relevance_buckets_;
+
+  static void InitializeHQPExperimentalParams();
 
   // Sets |also_do_hup_like_scoring_|,
   // |max_assigned_score_for_non_inlineable_matches_|, |bookmark_value_|,