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

chrome/browser/banners/app_banner_manager.h

Index: chrome/browser/banners/app_banner_manager.h
diff --git a/chrome/browser/banners/app_banner_manager.h b/chrome/browser/banners/app_banner_manager.h
index ed051fc05c76eafd4c094848bb77b4131beafed8..c1046a834f538dbe2aa1e03aa7c007720e93f45c 100644
--- a/chrome/browser/banners/app_banner_manager.h
+++ b/chrome/browser/banners/app_banner_manager.h
@@ -32,8 +32,8 @@ class AppBannerManager : public content::WebContentsObserver,
  public:
   static void DisableSecureSchemeCheckForTesting();
 
-  static void ForceEngagementWeightsForTesting(double direct_engagement,
-                                               double indirect_engagement);
+  static void SetEngagementWeights(double direct_engagement,
+                                   double indirect_engagement);
 
   // Returns whether or not the URLs match for everything except for the ref.
   static bool URLsAreForTheSamePage(const GURL& first, const GURL& second);