Use a single views::MenuConfig instance for each platform

ui/views/controls/menu/menu_separator.h

Index: ui/views/controls/menu/menu_separator.h
diff --git a/ui/views/controls/menu/menu_separator.h b/ui/views/controls/menu/menu_separator.h
index a0fd2c8170a8f86b67e42f5006f07e0ba91a1ee1..966e03fe9e1b7cd0ade35ffec0693a8295061587 100644
--- a/ui/views/controls/menu/menu_separator.h
+++ b/ui/views/controls/menu/menu_separator.h
@@ -15,9 +15,7 @@ class MenuItemView;
 
 class MenuSeparator : public View {
  public:
-  MenuSeparator(MenuItemView* parent, ui::MenuSeparatorType type)
-      : type_(type),
-        parent_menu_item_(parent) {}
+  explicit MenuSeparator(ui::MenuSeparatorType type) : type_(type) {}
 
   // View overrides.
   void OnPaint(gfx::Canvas* canvas) override;
@@ -32,9 +30,6 @@ class MenuSeparator : public View {
   // The type of the separator.
   const ui::MenuSeparatorType type_;
 
-  // Our parent.
-  MenuItemView* parent_menu_item_;
-
   DISALLOW_COPY_AND_ASSIGN(MenuSeparator);
 };