[gtk+] Adwaita: remove borders from flat frames

[Lapo Calamandrei <lapo src gnome org>]

commit 651328b0e4452d3fc40418b7470200e07e8d1038
Author: Lapo Calamandrei <calamandrei gmail com>
Date:   Fri Jun 27 14:53:31 2014 +0200

    Adwaita: remove borders from flat frames

 gtk/resources/theme/Adwaita/_common.scss           |    1 +
 gtk/resources/theme/Adwaita/gtk-contained-dark.css |    2 ++
 gtk/resources/theme/Adwaita/gtk-contained.css      |    2 ++
 3 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gtk/resources/theme/Adwaita/_common.scss b/gtk/resources/theme/Adwaita/_common.scss
index 0c50fa3..8350dc1 100644
--- a/gtk/resources/theme/Adwaita/_common.scss
+++ b/gtk/resources/theme/Adwaita/_common.scss
@@ -1613,6 +1613,7 @@ GtkLevelBar.vertical {
  **********/
 .frame {
   border: 1px solid $borders_color;
+  &.flat { border-style: none; }
   &:backdrop { border-color: $backdrop_borders_color; }
   padding: 0;
   &.action-bar {
diff --git a/gtk/resources/theme/Adwaita/gtk-contained-dark.css 
b/gtk/resources/theme/Adwaita/gtk-contained-dark.css
index 3b6ccc6..62ccb6f 100644
--- a/gtk/resources/theme/Adwaita/gtk-contained-dark.css
+++ b/gtk/resources/theme/Adwaita/gtk-contained-dark.css
@@ -2183,6 +2183,8 @@ GtkLevelBar.vertical {
 .frame {
   border: 1px solid #1c1f1f;
   padding: 0; }
+  .frame.flat {
+    border-style: none; }
   .frame:backdrop {
     border-color: #1e2222; }
   .frame.action-bar {
diff --git a/gtk/resources/theme/Adwaita/gtk-contained.css b/gtk/resources/theme/Adwaita/gtk-contained.css
index 6123cef..76341b2 100644
--- a/gtk/resources/theme/Adwaita/gtk-contained.css
+++ b/gtk/resources/theme/Adwaita/gtk-contained.css
@@ -2181,6 +2181,8 @@ GtkLevelBar.vertical {
 .frame {
   border: 1px solid #a1a1a1;
   padding: 0; }
+  .frame.flat {
+    border-style: none; }
   .frame:backdrop {
     border-color: #a8a8a8; }
   .frame.action-bar {