chromeos: fix focus for mushrome

ui/aura/test/mus/window_tree_client_private.h

Index: ui/aura/test/mus/window_tree_client_private.h
diff --git a/ui/aura/test/mus/window_tree_client_private.h b/ui/aura/test/mus/window_tree_client_private.h
index b0ad445818a13e7373d399ed496317972e910b24..f17b2b44c72cc500050fd192f70617167c09baa4 100644
--- a/ui/aura/test/mus/window_tree_client_private.h
+++ b/ui/aura/test/mus/window_tree_client_private.h
@@ -21,6 +21,7 @@ namespace ui {
 class Event;
 
 namespace mojom {
+class WindowManagerClient;
 class WindowTree;
 }
 }
@@ -65,6 +66,8 @@ class WindowTreeClientPrivate {
   void SetTreeAndClientId(ui::mojom::WindowTree* window_tree,
                           ClientSpecificId client_id);
 
+  void SetWindowManagerClient(ui::mojom::WindowManagerClient* client);
+
   bool HasPointerWatcher();
 
   Window* GetWindowByServerId(Id id);