Add Apps.AppListSearchResultDistanceFromOrigin UMA stat.

ui/app_list/views/search_result_tile_item_list_view.cc

Index: ui/app_list/views/search_result_tile_item_list_view.cc
diff --git a/ui/app_list/views/search_result_tile_item_list_view.cc b/ui/app_list/views/search_result_tile_item_list_view.cc
index 2816f1e108a242f6d88a759ffa6b3a679107320c..4218c99d85abb3dd25a23563abf22a8436bf04af 100644
--- a/ui/app_list/views/search_result_tile_item_list_view.cc
+++ b/ui/app_list/views/search_result_tile_item_list_view.cc
@@ -58,6 +58,15 @@ void SearchResultTileItemListView::OnContainerSelected(
   SetSelectedIndex(select_last ? num_results() - 1 : 0);
 }
 
+void SearchResultTileItemListView::NotifyFirstResultYIndex(int y_index) {
+  for (size_t i = 0; i < static_cast<size_t>(num_results()); ++i)
+    tile_views_[i]->result()->set_distance_from_origin(i + y_index);
+}
+
+int SearchResultTileItemListView::GetYSize() {
+  return num_results() ? 1 : 0;
+}
+
 int SearchResultTileItemListView::Update() {
   std::vector<SearchResult*> display_results =
       AppListModel::FilterSearchResultsByDisplayType(