[gtk+] testwidgetfocus: Make focused button more obvious

[Timm Bäder <baedert src gnome org>]

commit 8fa20f87e48fe1a7bb80f9c9664c2b718e1636c9
Author: Timm Bäder <mail baedert org>
Date:   Wed Nov 1 12:47:11 2017 +0100

    testwidgetfocus: Make focused button more obvious

 tests/testwidgetfocus.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/tests/testwidgetfocus.c b/tests/testwidgetfocus.c
index 8164759..978aee6 100644
--- a/tests/testwidgetfocus.c
+++ b/tests/testwidgetfocus.c
@@ -47,6 +47,10 @@ const char *css =
 "  background-color: white;"
 "  box-shadow: none;"
 "}"
+"focuswidget button:focus(visible) {"
+"  outline-width: 4px;"
+"  outline-color: yellow;"
+"}"
 "focuswidget button:hover {"
 "  background-color: black;"
 "  color: white;"