Native themes: Add menu separator part

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 ec5b30a6800a35197a7f5210787cb732e70118e2..b9718490f9ad7cd4682fdab5b9e879ec0bd902ba 100644
--- a/ui/native_theme/native_theme_base.cc
+++ b/ui/native_theme/native_theme_base.cc
@@ -186,6 +186,9 @@ void NativeThemeBase::Paint(SkCanvas* canvas,
     case kMenuPopupBackground:
       PaintMenuPopupBackground(canvas, rect.size(), extra.menu_background);
       break;
+    case kMenuPopupSeparator:
+      PaintMenuSeparator(canvas, state, rect, extra.menu_separator);
+      break;
     case kMenuItemBackground:
       PaintMenuItemBackground(canvas, state, rect, extra.menu_item);
       break;
@@ -776,6 +779,16 @@ void NativeThemeBase::PaintMenuItemBackground(
   // By default don't draw anything over the normal background.
 }
 
+void NativeThemeBase::PaintMenuSeparator(
+    SkCanvas* canvas,
+    State state,
+    const gfx::Rect& rect,
+    const MenuSeparatorExtraParams& menu_separator) const {
+  SkPaint paint;
+  paint.setColor(GetSystemColor(ui::NativeTheme::kColorId_MenuSeparatorColor));
+  canvas->drawRect(gfx::RectToSkRect(*menu_separator.paint_rect), paint);
+}
+
 void NativeThemeBase::PaintSliderTrack(SkCanvas* canvas,
                                        State state,
                                        const gfx::Rect& rect,