Implement app list folder management page UI.

ash/test/app_list_controller_test_api.cc

Index: ash/test/app_list_controller_test_api.cc
diff --git a/ash/test/app_list_controller_test_api.cc b/ash/test/app_list_controller_test_api.cc
index df21070f138d1073469848118f9eb5642853669c..7e2ac2d4b651dcda997afaf9a866286d07d55e4c 100644
--- a/ash/test/app_list_controller_test_api.cc
+++ b/ash/test/app_list_controller_test_api.cc
@@ -6,6 +6,11 @@
 
 #include "ash/test/shell_test_api.h"
 #include "ash/wm/app_list_controller.h"
+#include "ui/app_list/views/app_list_main_view.h"
+#include "ui/app_list/views/app_list_view.h"
+#include "ui/app_list/views/apps_container_view.h"
+#include "ui/app_list/views/apps_grid_view.h"
+#include "ui/app_list/views/contents_view.h"
 
 namespace ash {
 namespace test {
@@ -13,6 +18,11 @@ namespace test {
 AppListControllerTestApi::AppListControllerTestApi(Shell* shell)
     : app_list_controller_(ShellTestApi(shell).app_list_controller()) {}
 
+app_list::AppsGridView* AppListControllerTestApi::GetRootGridView() {
+  return view()->app_list_main_view()->contents_view()->
+      apps_container_view()->apps_grid_view();
+}
+
 app_list::AppListView* AppListControllerTestApi::view() {
   return app_list_controller_->view_;
 }