change the way windows are parented when their parent is set to NULL.

ui/aura/toplevel_window_container.h

 // Copyright (c) 2011 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_AURA_TOPLEVEL_WINDOW_CONTAINER_H_
 #define UI_AURA_TOPLEVEL_WINDOW_CONTAINER_H_
 #pragma once
 
 #include "ui/aura/window.h"
 #include "ui/aura/aura_export.h"
 
 namespace aura {
-namespace internal {
-
-class FocusManager;
 
 // A Window subclass that groups top-level windows.
 class AURA_EXPORT ToplevelWindowContainer : public Window {
  public:
   ToplevelWindowContainer();
   virtual ~ToplevelWindowContainer();
 
+  // Returns the topmost window to activate, ignoring |ignore|.
+  Window* GetTopmostWindowToActivate(Window* ignore) const;
+
   // Overridden from Window:
-  virtual bool IsToplevelWindowContainer() const OVERRIDE;
+  virtual ToplevelWindowContainer* AsToplevelWindowContainer() OVERRIDE;
+  virtual const ToplevelWindowContainer* AsToplevelWindowContainer() const
+      OVERRIDE;

[sky, 2011/10/07 19:59:45]

nit: wrap function name to avoid dangling OVERRIDE.

 
  private:
   DISALLOW_COPY_AND_ASSIGN(ToplevelWindowContainer);
 };
 
-}  // namespace internal
 }  // namespace aura
 
 #endif  // UI_AURA_TOPLEVEL_WINDOW_CONTAINER_H_