Makes NativeViewHostWin change the parent of the hwnd when

ui/base/win/hidden_window.h

Index: ui/base/win/hidden_window.h
diff --git a/ui/base/win/hidden_window.h b/ui/base/win/hidden_window.h
new file mode 100644
index 0000000000000000000000000000000000000000..e3189a6a688ddb84b386d321c9eb0ffc86c3366c
--- /dev/null
+++ b/ui/base/win/hidden_window.h
@@ -0,0 +1,20 @@
+// 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_BASE_WIN_HIDDEN_WINDOW_H_
+#define UI_BASE_WIN_HIDDEN_WINDOW_H_
+
+#include <windows.h>
+
+#include "ui/base/ui_export.h"
+
+namespace ui {
+
+// Returns an HWND that can be used as a temporary parent. The returned HWND is
+// never destroyed.
+UI_EXPORT HWND GetHiddenWindow();
+
+}  // namespace ui
+
+#endif  // UI_BASE_WIN_HIDDEN_WINDOW_H_