[gnome-builder] testui: add cancel button for unit tests

[Christian Hergert <chergert src gnome org>]

commit 4cf84552499cb2be2523423759f80c1ef5f9e28b
Author: Christian Hergert <chergert redhat com>
Date:   Sat Apr 27 17:42:19 2019 -0700

    testui: add cancel button for unit tests

 src/plugins/testui/gbp-test-output-panel.ui | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
---
diff --git a/src/plugins/testui/gbp-test-output-panel.ui b/src/plugins/testui/gbp-test-output-panel.ui
index cbd634fd5..f1f21c1a4 100644
--- a/src/plugins/testui/gbp-test-output-panel.ui
+++ b/src/plugins/testui/gbp-test-output-panel.ui
@@ -44,6 +44,23 @@
                 </child>
               </object>
             </child>
+            <child>
+              <object class="GtkButton" id="stop_button">
+                <property name="action-name">test-manager.cancel</property>
+                <property name="expand">false</property>
+                <property name="tooltip-text" translatable="yes">Cancel tests</property>
+                <property name="visible">true</property>
+                <style>
+                  <class name="flat"/>
+                </style>
+                <child>
+                  <object class="GtkImage">
+                    <property name="icon-name">process-stop-symbolic</property>
+                    <property name="visible">true</property>
+                  </object>
+                </child>
+              </object>
+            </child>
             <child>
               <object class="GtkButton" id="save_button">
                 <property name="action-name">test-output.save</property>