Reorder the NativeViews attached to a view via kViewHostKey according to the position of the view

chrome/browser/ui/views/dropdown_bar_host.h

Index: chrome/browser/ui/views/dropdown_bar_host.h
diff --git a/chrome/browser/ui/views/dropdown_bar_host.h b/chrome/browser/ui/views/dropdown_bar_host.h
index de30c67873e2d7e4438424ca028ed7ece60c59a2..77433c5e9a97fad4b73bc898aaa3ab8d4df82f97 100644
--- a/chrome/browser/ui/views/dropdown_bar_host.h
+++ b/chrome/browser/ui/views/dropdown_bar_host.h
@@ -181,6 +181,15 @@ class DropdownBarHost : public ui::AcceleratorTarget,
   // closed.
   scoped_ptr<views::ExternalFocusTracker> focus_tracker_;
 
+#if defined(USE_AURA)
+  // The host view is a view maintained by the drop down bar in |browser_view_|
+  // to denote the z-order of the drop down bar relative to child views of
+  // |browser_view_| which have layers and NativeViews attached to a child
+  // NativeViewHost of |browser_view_|.
+  // TODO: implement a similar mechanism for Windows.
+  scoped_ptr<views::View> host_view_;
+#endif  // USE_AURA
+
   // Host is the Widget implementation that is created and maintained by the
   // dropdown bar. It contains the DropdownBarView.
   scoped_ptr<views::Widget> host_;