Fix menu corners: the menu background was being painted as a rect when in fact,

ui/native_theme/native_theme_base.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_BASE_H_
 #define UI_NATIVE_THEME_NATIVE_THEME_BASE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "skia/ext/platform_canvas.h"
@@ skipping 68 matching lines @@
       State state,
       const gfx::Rect& rect,
       const TextFieldExtraParams& text) const;
 
   virtual void PaintMenuList(
       SkCanvas* canvas,
       State state,
       const gfx::Rect& rect,
       const MenuListExtraParams& menu_list) const;
 
-  virtual void PaintMenuPopupBackground(SkCanvas* canvas,
-                                        const gfx::Size& size) const;
+  virtual void PaintMenuPopupBackground(
+      SkCanvas* canvas,
+      const gfx::Size& size,
+      const MenuBackgroundExtraParams& menu_background) const;
 
   virtual void PaintMenuItemBackground(
       SkCanvas* canvas,
       State state,
       const gfx::Rect& rect,
       const MenuListExtraParams& menu_list) const;
 
   virtual void PaintSliderTrack(
       SkCanvas* canvas,
       State state,
@@ skipping 89 matching lines @@
 
   unsigned int scrollbar_width_;
   unsigned int scrollbar_button_length_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeThemeBase);
 };
 
 }  // namespace ui
 
 #endif  // UI_NATIVE_THEME_NATIVE_THEME_BASE_H_