Allow direct and indirect navigation values to be varied via field trial.

chrome/browser/banners/app_banner_settings_helper.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_BANNERS_APP_BANNER_SETTINGS_HELPER_H_
 #define CHROME_BROWSER_BANNERS_APP_BANNER_SETTINGS_HELPER_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 114 matching lines @@
   // Set the minimum number of minutes between banner visits that will
   // trigger a could show banner event. This must be less than the
   // number of minutes in a day, and evenly divide the number of minutes
   // in a day.
   static void SetMinimumMinutesBetweenVisits(unsigned int minutes);
 
   // Bucket a given time to the given resolution in local time.
   static base::Time BucketTimeToResolution(base::Time time,
                                            unsigned int minutes);
 
+  // Queries a field trial for updates to the default engagement values assigned
+  // to direct and indirect navigations.
+  static void UpdateEngagementWeights();
+
   // Queries a field trial for updates to the default number of minutes between
   // site visits counted for the purposes of displaying a banner.
   static void UpdateMinutesBetweenVisits();
 
+  // Updates all values from field trial.
+  static void UpdateFromFieldTrial();
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AppBannerSettingsHelper);
 };
 
 #endif  // CHROME_BROWSER_BANNERS_APP_BANNER_SETTINGS_HELPER_H_