Fullscreen can't use the desktop as a parent in metro mode

ui/base/win/hwnd_util.h

 // 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_HWND_UTIL_H_
 #define UI_BASE_WIN_HWND_UTIL_H_
 #pragma once
 
 #include <windows.h>
 
@@ skipping 29 matching lines @@
                                    const gfx::Size& pref);
 
 // If |hwnd| is NULL logs various thing and CHECKs. Invoke right after calling
 // CreateWindow.
 UI_EXPORT void CheckWindowCreated(HWND hwnd);
 
 // Shows the system menu for |window| and sends the selected command (if the
 // user selected something.
 UI_EXPORT void ShowSystemMenu(HWND window, int screen_x, int screen_y);
 
+// Returns the root window you can use to parent a window. Note that in some
+// cases we create child windows not parented to its final container so in
+// those very few cases you should pass true in |is_child_window|.
+UI_EXPORT HWND GetRootWindow(bool is_child_window);

[sky, 2012/05/01 15:40:39]

Is there another name we could use for this? RootWindow is also the name of a
class aura.

[cpu_(ooo_6.6-7.5), 2012/05/01 20:53:12]

Yeah, I noticed. Does not seem to conflict because of namespaces, but I see it
can be confusing. That is why I renamed from RootWindow to GetRootWindow.

How about 
GetOSRootWindow?

GetTopLevelWindow, the other choice is used in  src/remoting/host

Naming is hard.

+
 }  // namespace ui
 
 #endif  // UI_BASE_WIN_HWND_UTIL_H_