Use NativeTheme to draw vertical menu separators.

ui/native_theme/native_theme.h

 // Copyright (c) 2012 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_NATIVE_THEME_NATIVE_THEME_H_
 #define UI_NATIVE_THEME_NATIVE_THEME_H_
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "build/build_config.h"
@@ skipping 301 matching lines @@
     kColorId_TextOnProminentButtonColor,
     // MenuItem
     kColorId_EnabledMenuItemForegroundColor,
     kColorId_DisabledMenuItemForegroundColor,
     kColorId_SelectedMenuItemForegroundColor,
     kColorId_FocusedMenuItemBackgroundColor,
     kColorId_MenuItemSubtitleColor,
     kColorId_MenuSeparatorColor,
     kColorId_MenuBackgroundColor,
     kColorId_MenuBorderColor,
-    // MenuButton - buttons in wrench menu
-    kColorId_EnabledMenuButtonBorderColor,
-    kColorId_FocusedMenuButtonBorderColor,
-    kColorId_HoverMenuButtonBorderColor,
     // Label
     kColorId_LabelEnabledColor,
     kColorId_LabelDisabledColor,
     kColorId_LabelTextSelectionColor,
     kColorId_LabelTextSelectionBackgroundFocused,
     // Link
     kColorId_LinkDisabled,
     kColorId_LinkEnabled,
     kColorId_LinkPressed,
     // Separator
@@ skipping 95 matching lines @@
  private:
   // Observers to notify when the native theme changes.
   base::ObserverList<NativeThemeObserver> native_theme_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeTheme);
 };
 
 }  // namespace ui
 
 #endif  // UI_NATIVE_THEME_NATIVE_THEME_H_