[gtk/wip/matthiasc/popup2: 104/126] Give popover menus a background

[Matthias Clasen <matthiasc src gnome org>]

commit db8cea841243750b0789e0fa7d9fd8af93ccc293
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Mar 24 11:41:55 2019 -0400

    Give popover menus a background
    
    This makes the hover highlight on menu items visible.

 gtk/theme/Adwaita/_common.scss | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index 8075197c41..2eaf96d490 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -4716,3 +4716,7 @@ popover.emoji-completion contents row box {
 popover.emoji-completion .emoji:hover {
   background-color: $popover_hover_color;
 }
+
+popover.menu {
+  background-color: lightgray;
+}