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

ui/app_list/search_controller.cc

Index: ui/app_list/search_controller.cc
diff --git a/ui/app_list/search_controller.cc b/ui/app_list/search_controller.cc
index 9894492aac597c89ea6fd4126a51b65708a93156..d2e16614afb03c5d5a76df4cc395cde180929f1c 100644
--- a/ui/app_list/search_controller.cc
+++ b/ui/app_list/search_controller.cc
@@ -99,12 +99,16 @@ void SearchController::InvokeResultAction(SearchResult* result,
   result->InvokeAction(action_index, event_flags);
 }
 
-size_t SearchController::AddGroup(size_t max_results, double boost) {
-  return mixer_->AddGroup(max_results, boost);
+size_t SearchController::AddGroup(size_t max_results,
+                                  double boost,
+                                  double multiplier) {
+  return mixer_->AddGroup(max_results, boost, multiplier);
 }
 
-size_t SearchController::AddOmniboxGroup(size_t max_results, double boost) {
-  return mixer_->AddOmniboxGroup(max_results, boost);
+size_t SearchController::AddOmniboxGroup(size_t max_results,
+                                         double boost,
+                                         double multiplier) {
+  return mixer_->AddOmniboxGroup(max_results, boost, multiplier);
 }
 
 void SearchController::AddProvider(size_t group_id,