Makes visbility inherited. That is, in order for a window to be

ui/aura/window.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_WINDOW_H_
 #define UI_AURA_WINDOW_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 44 matching lines @@
 
   const std::string& name() const { return name_; }
   void set_name(const std::string& name) { name_ = name; }
 
   ui::Layer* layer() { return layer_.get(); }
   const ui::Layer* layer() const { return layer_.get(); }
 
   // Changes the visibility of the window.
   void Show();
   void Hide();
-  bool visible() const { return visible_; }
+  // Returns true if this window and all its ancestors are visible.
+  bool IsVisible() const;
 
   // Assigns a LayoutManager to size and place child windows.
   // The Window takes ownership of the LayoutManager.
   void SetLayoutManager(LayoutManager* layout_manager);
 
   // Changes the bounds of the window.
   void SetBounds(const gfx::Rect& new_bounds);
   const gfx::Rect& bounds() const;
 
   // Marks the a portion of window as needing to be painted.
@@ skipping 96 matching lines @@
   void SetVisible(bool visible);
 
   // Schedules a paint for the Window's entire bounds.
   void SchedulePaint();
 
   // Overridden from ui::LayerDelegate:
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE;
 
   WindowDelegate* delegate_;
 
-  bool visible_;
-
   scoped_ptr<ui::Layer> layer_;
 
   // The Window's parent.
   // TODO(beng): Implement NULL-ness for toplevels.
   Window* parent_;
 
   // Child windows. Topmost is last.
   Windows children_;
 
   int id_;
   std::string name_;
 
   scoped_ptr<EventFilter> event_filter_;
   scoped_ptr<LayoutManager> layout_manager_;
 
   void* user_data_;
 
   // When true, events are not sent to windows behind this one in the z-order,
   // provided this window has children. See set_consumes_events().
   bool consumes_events_;
 
   DISALLOW_COPY_AND_ASSIGN(Window);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_H_