Make NetworkMenuModel a ui::MenuModel again.

views/controls/menu/menu_item_view.cc

Index: views/controls/menu/menu_item_view.cc
diff --git a/views/controls/menu/menu_item_view.cc b/views/controls/menu/menu_item_view.cc
index eff0e39ea07b23120cea0f31f4e87eb02964d2e7..f928d50ed610ecc93040ffa88676a8ec4bee3c47 100644
--- a/views/controls/menu/menu_item_view.cc
+++ b/views/controls/menu/menu_item_view.cc
@@ -508,6 +508,14 @@ int MenuItemView::GetAcceleratorTextWidth() {
   return text.empty() ? 0 : GetFont().GetStringWidth(text);
 }
 
+void MenuItemView::SetMargins(int top_margin, int bottom_margin) {
+  top_margin_ = top_margin;
+  bottom_margin_ = bottom_margin;
+
+  // invalidate GetPreferredSize() cache
+  pref_size_.SetSize(0,0);
+}
+
 MenuItemView::MenuItemView(MenuItemView* parent,
                            int command,
                            MenuItemView::Type type)