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

ui/native_theme/native_theme_base.cc

Index: ui/native_theme/native_theme_base.cc
diff --git a/ui/native_theme/native_theme_base.cc b/ui/native_theme/native_theme_base.cc
index 7a833f6f889572f68b5757de09f67f349dd446bc..70dbcc4eadab7aee6e2ad74533dad513e2f4537a 100644
--- a/ui/native_theme/native_theme_base.cc
+++ b/ui/native_theme/native_theme_base.cc
@@ -176,7 +176,7 @@ void NativeThemeBase::Paint(SkCanvas* canvas,
       NOTIMPLEMENTED();
       break;
     case kMenuPopupBackground:
-      PaintMenuPopupBackground(canvas, rect.size());
+      PaintMenuPopupBackground(canvas, rect.size(), extra.menu_background);
       break;
     case kMenuPopupGutter:
     case kMenuPopupSeparator:
@@ -867,8 +867,10 @@ void NativeThemeBase::PaintMenuList(
   canvas->drawPath(path, paint);
 }
 
-void NativeThemeBase::PaintMenuPopupBackground(SkCanvas* canvas,
-                                               const gfx::Size& size) const {
+void NativeThemeBase::PaintMenuPopupBackground(
+    SkCanvas* canvas,
+    const gfx::Size& size,
+    const MenuBackgroundExtraParams& menu_background) const {
   canvas->drawColor(kMenuPopupBackgroundColor, SkXfermode::kSrc_Mode);
 }