Remove oak windows and its flags.

ui/oak/oak_tree_model.h

Index: ui/oak/oak_tree_model.h
diff --git a/ui/oak/oak_tree_model.h b/ui/oak/oak_tree_model.h
deleted file mode 100644
index f68912d8b841fa82cdb8dce4deae51318a571936..0000000000000000000000000000000000000000
--- a/ui/oak/oak_tree_model.h
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright (c) 2012 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_OAK_OAK_TREE_MODEL_H_
-#define UI_OAK_OAK_TREE_MODEL_H_
-
-#include "base/compiler_specific.h"
-#include "ui/base/models/tree_node_model.h"
-
-namespace aura {
-class Window;
-}
-
-namespace oak {
-namespace internal {
-
-typedef ui::TreeNodeWithValue<aura::Window*> WindowNode;
-typedef ui::TreeNodeModel<WindowNode> TreeOfWindows;
-
-TreeOfWindows* GenerateModel(aura::Window* root);
-
-}  // namespace internal
-}  // namespace oak
-
-#endif  // UI_OAK_OAK_TREE_MODEL_H_