Makes it so child views of menuitemview can be traversed with the

views/controls/menu/submenu_view.h

 // Copyright (c) 2010 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 VIEWS_CONTROLS_MENU_SUBMENU_VIEW_H_
 #define VIEWS_CONTROLS_MENU_SUBMENU_VIEW_H_
 
 #include "views/controls/menu/menu_delegate.h"
 #include "views/view.h"
 
@@ skipping 56 matching lines @@
   virtual int OnPerformDrop(const DropTargetEvent& event);
 
   // Scrolls on menu item boundaries.
   virtual bool OnMouseWheel(const MouseWheelEvent& e);
 
   // Returns true if the menu is showing.
   bool IsShowing();
 
   // Shows the menu at the specified location. Coordinates are in screen
   // coordinates. max_width gives the max width the view should be.
-  void ShowAt(gfx::NativeWindow parent, const gfx::Rect& bounds, bool do_capture);
+  void ShowAt(gfx::NativeWindow parent,
+              const gfx::Rect& bounds,
+              bool do_capture);
 
   // Resets the bounds of the submenu to |bounds|.
   void Reposition(const gfx::Rect& bounds);
 
   // Closes the menu, destroying the host.
   void Close();
 
   // Hides the hosting window.
   //
   // The hosting window is hidden first, then deleted (Close) when the menu is
@@ skipping 68 matching lines @@
 
   // Ancestor of the SubmenuView, lazily created.
   MenuScrollViewContainer* scroll_view_container_;
 
   DISALLOW_COPY_AND_ASSIGN(SubmenuView);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_MENU_SUBMENU_VIEW_H_