Reset the app list when it is shown on Windows and Linux.

ui/app_list/views/apps_grid_view.h

Index: ui/app_list/views/apps_grid_view.h
diff --git a/ui/app_list/views/apps_grid_view.h b/ui/app_list/views/apps_grid_view.h
index 22d8bb19ed97f35cc4101eb54222b891672bceeb..a0f24a0523ca222a475b2b228998609ea77146ea 100644
--- a/ui/app_list/views/apps_grid_view.h
+++ b/ui/app_list/views/apps_grid_view.h
@@ -83,6 +83,9 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
   int cols() { return cols_; }
   int rows_per_page() { return rows_per_page_; }
 
+  // This resets the grid view to a fresh state for showing the app list.
+  void ResetForShowApps();
+
   // Sets |model| to use. Note this does not take ownership of |model|.
   void SetModel(AppListModel* model);