Omnibox: Create HistoryQuickProvider new scoring field trial.

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 26440141c547eda8ce2afc3c137f543083bad53a..4ddd73b7bae9789aa0e7ae83f95869e5bfe03106 100644
--- a/chrome/browser/history/scored_history_match.h
+++ b/chrome/browser/history/scored_history_match.h
@@ -97,6 +97,10 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
   static float GetPopularityScore(int typed_count,
                                   int visit_count);
 
+  // Sets use_new_scoring based on command line flags and/or
+  // field trial state.
+  static void InitializeNewScoringField();
+
   // End of functions used only in "new" scoring --------------------------
 
   // An interim score taking into consideration location and completeness
@@ -127,7 +131,7 @@ struct ScoredHistoryMatch : public history::HistoryMatch {
   static float* raw_term_score_to_topicality_score;
 
   // Allows us to determing setting for use_new_scoring_ only once.
-  static bool initialized;
+  static bool initialized_;
 
   // Whether to use new-score or old-scoring.  Set in the constructor
   // by examining command line flags.