Revert of Allows menu host windows to be enumerated in DragTargetWindowFinder

ui/base/x/x11_menu_list.h

Index: ui/base/x/x11_menu_list.h
diff --git a/ui/base/x/x11_menu_list.h b/ui/base/x/x11_menu_list.h
deleted file mode 100644
index 4e8476aea088b75cf387925d2f459e70522e7586..0000000000000000000000000000000000000000
--- a/ui/base/x/x11_menu_list.h
+++ /dev/null
@@ -1,48 +0,0 @@
-// Copyright (c) 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef UI_BASE_X_X11_MENU_LIST_H_
-#define UI_BASE_X_X11_MENU_LIST_H_
-
-#include <vector>
-
-#include "base/basictypes.h"
-#include "ui/base/ui_base_export.h"
-#include "ui/gfx/x/x11_types.h"
-
-typedef unsigned long Atom;
-
-// A process wide singleton cache for X menus.
-template <typename T> struct DefaultSingletonTraits;
-
-namespace ui {
-
-// Keeps track of created and destroyed top level menu windows.
-class UI_BASE_EXPORT XMenuList {
- public:
-  static XMenuList* GetInstance();
-
-  // Checks if |menu| has _NET_WM_WINDOW_TYPE property set to
-  // "_NET_WM_WINDOW_TYPE_MENU" atom and if so caches it.
-  void MaybeRegisterMenu(XID menu);
-
-  // Finds |menu| in cache and if found removes it.
-  void MaybeUnregisterMenu(XID menu);
-
-  // Inserts cached menu XIDs at the beginning of |stack|.
-  void InsertMenuWindowXIDs(std::vector<XID>* stack);
-
- private:
-  friend struct DefaultSingletonTraits<XMenuList>;
-  XMenuList();
-  ~XMenuList();
-
-  std::vector<XID> menus_;
-  ::Atom menu_type_atom_;
-  DISALLOW_COPY_AND_ASSIGN(XMenuList);
-};
-
-}  // namespace ui
-
-#endif  // UI_BASE_X_X11_MENU_LIST_H_