Fix menu scroll indicators and highlights overlapping the menu border.

ui/views/round_rect_painter.h

Index: ui/views/round_rect_painter.h
diff --git a/ui/views/round_rect_painter.h b/ui/views/round_rect_painter.h
index f52624a425a89b7bc10a5548914ab844965f9ce7..17c51d0fc60add21bbb0a11dbe89f4adb33c5430 100644
--- a/ui/views/round_rect_painter.h
+++ b/ui/views/round_rect_painter.h
@@ -21,6 +21,8 @@ namespace views {
 // Painter to draw a border with rounded corners.
 class VIEWS_EXPORT RoundRectPainter : public Painter {
  public:
+  enum { kBorderWidth = 1 };
+
   RoundRectPainter(SkColor border_color, int corner_radius);
   ~RoundRectPainter() override;