Convert TrayEventFilter to wm common types

ash/sysui/shell_delegate_mus.cc

Index: ash/sysui/shell_delegate_mus.cc
diff --git a/ash/sysui/shell_delegate_mus.cc b/ash/sysui/shell_delegate_mus.cc
index 05b0306eb358d350321fa681d3a54294f4889fef..ffb310188ab02d205f2ff487909afcf221f1d8ce 100644
--- a/ash/sysui/shell_delegate_mus.cc
+++ b/ash/sysui/shell_delegate_mus.cc
@@ -10,7 +10,6 @@
 #include "ash/gpu_support_stub.h"
 #include "ash/media_delegate.h"
 #include "ash/sysui/app_list_presenter_mus.h"
-#include "ash/sysui/container_delegate_mus.h"
 #include "ash/sysui/context_menu_mus.h"
 #include "ash/sysui/pointer_watcher_delegate_mus.h"
 #include "ash/sysui/shelf_delegate_mus.h"
@@ -210,10 +209,6 @@ MediaDelegate* ShellDelegateMus::CreateMediaDelegate() {
   return new MediaDelegateStub;
 }
 
-std::unique_ptr<ContainerDelegate> ShellDelegateMus::CreateContainerDelegate() {
-  return base::WrapUnique(new ContainerDelegateMus);
-}
-
 std::unique_ptr<PointerWatcherDelegate>
 ShellDelegateMus::CreatePointerWatcherDelegate() {
   return base::WrapUnique(new PointerWatcherDelegateMus);