ash: Cleanup class/struct forward declarations

ash/app_list/app_list_presenter_delegate.h

Index: ash/app_list/app_list_presenter_delegate.h
diff --git a/ash/app_list/app_list_presenter_delegate.h b/ash/app_list/app_list_presenter_delegate.h
index 21775ea56f4e5051f2f24e3bd8c20c469f47e77b..be6c897f73c7ab40eaeda8a234f79fb0e157ab08 100644
--- a/ash/app_list/app_list_presenter_delegate.h
+++ b/ash/app_list/app_list_presenter_delegate.h
@@ -16,7 +16,6 @@
 #include "ui/keyboard/keyboard_controller_observer.h"
 
 namespace app_list {
-class ApplicationDragAndDropHost;
 class AppListPresenter;
 class AppListView;
 class AppListViewDelegateFactory;
@@ -28,10 +27,6 @@ class LocatedEvent;
 
 namespace ash {
 
-namespace test {
-class AppListPresenterAshTestApi;
-}
-
 // Non-Mus+ash implementation of AppListPresetnerDelegate.
 // Responsible for laying out the app list UI as well as updating the Shelf
 // launch icon as the state of the app list changes. Listens to shell events