[epiphany/wip/exalm/gtk4-cleanups-3: 11/18] Stop using GtkButton:relief

[Alexander Mikhaylenko <alexm src gnome org>]

commit 28646b9a6e1e1a15b353436c8a5afe43cd9efc13
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Thu Dec 2 03:38:43 2021 +0500

    Stop using GtkButton:relief
    
    This will go away in GTK4, use .flat style class instead.

 lib/ephy-notification.c                  | 2 +-
 src/bookmarks/ephy-bookmark-properties.c | 2 +-
 src/ephy-history-dialog.c                | 1 -
 src/resources/gtk/bookmark-row.ui        | 4 +++-
 src/resources/gtk/page-row.ui            | 1 -
 5 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/lib/ephy-notification.c b/lib/ephy-notification.c
index c7f732b05..6f017326c 100644
--- a/lib/ephy-notification.c
+++ b/lib/ephy-notification.c
@@ -147,10 +147,10 @@ ephy_notification_init (EphyNotification *self)
 
   self->close_button = gtk_button_new ();
   g_object_set (self->close_button,
-                "relief", GTK_RELIEF_NONE,
                 "focus-on-click", FALSE,
                 "margin", 6,
                 NULL);
+  gtk_style_context_add_class (gtk_widget_get_style_context (self->close_button), "flat");
   gtk_grid_attach (GTK_GRID (self->grid), self->close_button, 1, 0, 1, 2);
 
   image = gtk_image_new_from_icon_name ("window-close-symbolic", GTK_ICON_SIZE_BUTTON);
diff --git a/src/bookmarks/ephy-bookmark-properties.c b/src/bookmarks/ephy-bookmark-properties.c
index da1f4c6a0..67c7dd3bb 100644
--- a/src/bookmarks/ephy-bookmark-properties.c
+++ b/src/bookmarks/ephy-bookmark-properties.c
@@ -200,7 +200,7 @@ ephy_bookmark_properties_create_tag_widget (EphyBookmarkProperties *self,
                           gtk_image_new_from_icon_name ("window-close-symbolic",
                                                         GTK_ICON_SIZE_MENU));
     gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
-    gtk_button_set_relief (GTK_BUTTON (button), GTK_RELIEF_NONE);
+    gtk_style_context_add_class (gtk_widget_get_style_context (button), "flat");
     gtk_box_pack_start (GTK_BOX (box), button, FALSE, TRUE, 0);
     g_signal_connect_object (button, "clicked",
                              G_CALLBACK (ephy_bookmark_properties_tag_widget_button_clicked_cb),
diff --git a/src/ephy-history-dialog.c b/src/ephy-history-dialog.c
index 1fc33860d..89a279fb7 100644
--- a/src/ephy-history-dialog.c
+++ b/src/ephy-history-dialog.c
@@ -457,7 +457,6 @@ create_row (EphyHistoryDialog *self,
   g_object_set_data (G_OBJECT (row), "check-button", check_button);
   gtk_widget_set_valign (check_button, GTK_ALIGN_CENTER);
   gtk_widget_set_tooltip_text (check_button, _("Remove the selected pages from history"));
-  gtk_button_set_relief (GTK_BUTTON (check_button), GTK_RELIEF_NONE);
   g_signal_connect (check_button, "toggled", G_CALLBACK (row_check_button_toggled), self);
 
   /* Copy URL button */
diff --git a/src/resources/gtk/bookmark-row.ui b/src/resources/gtk/bookmark-row.ui
index 2c6a18821..21372c7fc 100644
--- a/src/resources/gtk/bookmark-row.ui
+++ b/src/resources/gtk/bookmark-row.ui
@@ -27,13 +27,15 @@
           <object class="GtkButton" id="properties_button">
             <property name="visible">True</property>
             <property name="receives_default">False</property>
-            <property name="relief">none</property>
             <child>
               <object class="GtkImage">
                 <property name="visible">True</property>
                 <property name="icon_name">emblem-system-symbolic</property>
               </object>
             </child>
+            <style>
+              <class name="flat"/>
+            </style>
           </object>
         </child>
       </object>
diff --git a/src/resources/gtk/page-row.ui b/src/resources/gtk/page-row.ui
index 72ab0780b..0cb1a93e5 100644
--- a/src/resources/gtk/page-row.ui
+++ b/src/resources/gtk/page-row.ui
@@ -60,7 +60,6 @@
                 <property name="receives_default">False</property>
                 <property name="tooltip_text" translatable="yes">Close page</property>
                 <property name="valign">center</property>
-                <property name="relief">none</property>
                 <signal name="clicked" handler="close_clicked_cb" swapped="yes"/>
                 <child>
                   <object class="GtkImage">