Omnibox - Refactor |relevance_buckets| to Remove Memory Leak on Exit

components/omnibox/browser/omnibox_field_trial.h

Index: components/omnibox/browser/omnibox_field_trial.h
diff --git a/components/omnibox/browser/omnibox_field_trial.h b/components/omnibox/browser/omnibox_field_trial.h
index c4c6afe7d1a2e68a7720a87ff9c0894b9d979ab5..ef9f8d7791924f47cd1e871a257c4ec6f572fe38 100644
--- a/components/omnibox/browser/omnibox_field_trial.h
+++ b/components/omnibox/browser/omnibox_field_trial.h
@@ -270,22 +270,17 @@ class OmniboxFieldTrial {
   // 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
+  // Returns the scoring buckets for HQP experiments. Returns an empty string
+  // in case |kHQPExperimentalScoringBucketsParam| 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.
+  // Returns the topicality threshold for HQP experiments. Returns 0.8 if

[Peter Kasting, 2016/12/10 02:31:15]

Nit: I dunno if it would be clearer to say "returns a default value of 0.8
if..."?

[Mark P, 2016/12/11 04:57:22]

I agree.  Made two changes: added the mention of "default" and removed the
reference to the parameter name.  None of the other trials here mention the
parameter name.

+  // |kHQPExperimentalScoringTopicalityThresholdParam| is not specified in the
+  // field trial.
   static float HQPExperimentalTopicalityThreshold();
 
   // ---------------------------------------------------------
@@ -411,7 +406,6 @@ class OmniboxFieldTrial {
   static const char kHUPNewScoringVisitedCountUseDecayFactorParam[];
 
   // Parameter names used by the HQP experimental scoring experiments.
-  static const char kHQPExperimentalScoringEnabledParam[];
   static const char kHQPExperimentalScoringBucketsParam[];
   static const char kHQPExperimentalScoringTopicalityThresholdParam[];