Use NativeTheme to draw vertical menu separators.

ui/views/controls/menu/menu_separator.cc

 // 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.
 
 #include "ui/views/controls/menu/menu_separator.h"
 
 #include "build/build_config.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/canvas.h"
 #include "ui/native_theme/native_theme.h"
@@ skipping 34 matching lines @@
   float device_scale = display::win::GetDPIScale();
   bool is_fractional_scale =
       (device_scale - static_cast<int>(device_scale) != 0);
   if (is_fractional_scale && paint_rect.y() == 0)
     paint_rect.set_y(1);
 #endif
 
   ui::NativeTheme::ExtraParams params;
   params.menu_separator.paint_rect = &paint_rect;
   params.menu_separator.type = type_;
-  GetNativeTheme()->Paint(
-      canvas->sk_canvas(), ui::NativeTheme::kMenuPopupSeparator,
-      ui::NativeTheme::kNormal, gfx::Rect(bounds().size()), params);
+  GetNativeTheme()->Paint(canvas->sk_canvas(),
+                          ui::NativeTheme::kMenuPopupSeparator,
+                          ui::NativeTheme::kNormal, GetLocalBounds(), params);
 }
 
 gfx::Size MenuSeparator::GetPreferredSize() const {
   const MenuConfig& menu_config = MenuConfig::instance();
   int height = menu_config.separator_height;
   switch (type_) {
     case ui::SPACING_SEPARATOR:
       height = menu_config.separator_spacing_height;
       break;
     case ui::LOWER_SEPARATOR:
       height = menu_config.separator_lower_height;
       break;
     case ui::UPPER_SEPARATOR:
       height = menu_config.separator_upper_height;
       break;
     default:
       height = menu_config.separator_height;
       break;
   }
   return gfx::Size(10,  // Just in case we're the only item in a menu.
                    height);
 }
 
 }  // namespace views