App launcher: Added Finch experiment for the search ranking algorithm.

ui/app_list/search_controller.h

Index: ui/app_list/search_controller.h
diff --git a/ui/app_list/search_controller.h b/ui/app_list/search_controller.h
index c59564aad185d38e3ad8df603502d27e3000628a..f1e45d5fe1f2b135c6f80ebc6c049eb7f9485892 100644
--- a/ui/app_list/search_controller.h
+++ b/ui/app_list/search_controller.h
@@ -40,10 +40,10 @@ class APP_LIST_EXPORT SearchController {
                           int event_flags);
 
   // Adds a new mixer group. See Mixer::AddGroup.
-  size_t AddGroup(size_t max_results, double boost);
+  size_t AddGroup(size_t max_results, double boost, double multiplier);
 
   // Adds a new mixer group. See Mixer::AddOmniboxGroup.
-  size_t AddOmniboxGroup(size_t max_results, double boost);
+  size_t AddOmniboxGroup(size_t max_results, double boost, double multiplier);
 
   // Takes ownership of |provider| and associates it with given mixer group.
   void AddProvider(size_t group_id, scoped_ptr<SearchProvider> provider);