[gtk] Add devel style to demos

[Matthias Clasen <matthiasc src gnome org>]

commit ca9aa23619fe7b1fdceaf82b3c065ae5e7356727
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Sep 5 20:10:41 2018 -0400

    Add devel style to demos
    
    Lets show this off. Its cool.

 demos/gtk-demo/main.ui                 | 1 +
 demos/icon-browser/window.ui           | 1 +
 demos/widget-factory/widget-factory.ui | 3 ++-
 3 files changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/demos/gtk-demo/main.ui b/demos/gtk-demo/main.ui
index 086420a522..cf8f9298fb 100644
--- a/demos/gtk-demo/main.ui
+++ b/demos/gtk-demo/main.ui
@@ -16,6 +16,7 @@
     </columns>
   </object>
   <object class="GtkApplicationWindow" id="window">
+    <style><class name="devel"/></style>
     <property name="default-width">800</property>
     <property name="default-height">600</property>
     <property name="title">GTK+ Demo</property>
diff --git a/demos/icon-browser/window.ui b/demos/icon-browser/window.ui
index ae81f4af49..d060f97c38 100644
--- a/demos/icon-browser/window.ui
+++ b/demos/icon-browser/window.ui
@@ -6,6 +6,7 @@
     <property name="child-model">store</property>
   </object>
   <template class="IconBrowserWindow" parent="GtkApplicationWindow">
+    <style><class name="devel"/></style>
     <property name="title" translatable="yes">Icon Browser</property>
     <property name="default-width">1024</property>
     <property name="default-height">768</property>
diff --git a/demos/widget-factory/widget-factory.ui b/demos/widget-factory/widget-factory.ui
index 2bfa467a5b..55de27533f 100644
--- a/demos/widget-factory/widget-factory.ui
+++ b/demos/widget-factory/widget-factory.ui
@@ -396,6 +396,7 @@ Suspendisse feugiat quam quis dolor accumsan cursus.</property>
     </columns>
   </object>
   <object class="GtkApplicationWindow" id="window">
+    <style><class name="devel"/></style>
     <property name="title">GTK+ Widget Factory</property>
     <child type="titlebar">
       <object class="GtkHeaderBar" id="headerbar1">
@@ -3583,4 +3584,4 @@ bad things might happen.</property>
       </object>
     </child>
   </object>
-</interface>
\ No newline at end of file
+</interface>