[gtk/dnd-gestures-2] Adwaita: Add drop highlight for iconview items

[Matthias Clasen <matthiasc src gnome org>]

commit b63a991e89d1311d95f6394c3ceb76d64640c04b
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Jan 6 21:25:49 2020 -0500

    Adwaita: Add drop highlight for iconview items

 gtk/theme/Adwaita/_common.scss | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index bad7cfc929..02629ac2d8 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -142,7 +142,15 @@ textview {
 
 textview border { background-color: mix($bg_color, $base_color, 50%); }
 
-iconview { @extend .view; }
+iconview { 
+  @extend .view;
+
+  &:drop(active) {
+    border-style: solid;
+    border-width: 1px;
+    border-color: $selected_borders_color;
+  }
+}
 
 .rubberband,
 rubberband {