Adding knobs on HQP provider.

components/omnibox/omnibox_field_trial.h

Index: components/omnibox/omnibox_field_trial.h
diff --git a/components/omnibox/omnibox_field_trial.h b/components/omnibox/omnibox_field_trial.h
index 5a439e2f384a6dd62e2d1a5ceba56938d58b8325..4eebf644f256f0ac23d759b94970058b856dc1e4 100644
--- a/components/omnibox/omnibox_field_trial.h
+++ b/components/omnibox/omnibox_field_trial.h
@@ -270,6 +270,28 @@ class OmniboxFieldTrial {
                                         int* polling_delay_ms);
 
   // ---------------------------------------------------------
+  // For HQP scoring related experiments to control the topicality and scoring
+  // ranges of relevancy scores.
+
+  // Returns true if HQP experimental scoring is enabled. Returns false if
+  // |kHQPExperimentalScoringEnabledParam| is not specified in the field trial.
+  static bool HQPExperimentalScoringEnabled();
+
+  // Returns the scoring buckets for HQP experiments. Returns empty string
+  // in case |kHQPExperimentalScoringBucketsParam| or
+  // |kHQPExperimentalScoringEnabledParam| is not specified in the
+  // field trial. Scoring buckets are stored in string form giving mapping from
+  // (topicality_score, frequency_score) to final relevance score.
+  // Please see GetRelevancyScore() under
+  // chrome/browser/history::ScoredHistoryMatch for details.
+  static std::string HQPExperimentalScoringBuckets();
+
+  // Returns the topicality threshold for HQP experiments. Returns -1 if
+  // |kHQPExperimentalScoringTopicalityThresholdParam| or
+  // |kHQPExperimentalScoringEnabledParam| is not specified in the field trial.
+  static float HQPExperimentalTopicalityThreshold();
+
+  // ---------------------------------------------------------
   // Exposed publicly for the sake of unittests.
   static const char kBundledExperimentFieldTrialName[];
   // Rule names used by the bundled experiment.
@@ -298,6 +320,11 @@ class OmniboxFieldTrial {
   static const char kHUPNewScoringVisitedCountHalfLifeTimeParam[];
   static const char kHUPNewScoringVisitedCountScoreBucketsParam[];
 
+  // Parameter names used by the HQP experimental scoring experiments.
+  static const char kHQPExperimentalScoringEnabledParam[];
+  static const char kHQPExperimentalScoringBucketsParam[];
+  static const char kHQPExperimentalScoringTopicalityThresholdParam[];
+
   // The amount of time to wait before sending a new suggest request after the
   // previous one unless overridden by a field trial parameter.
   // Non-const because some unittests modify this value.