Add a GtkSpinner testcase

tests/a11y/Makefile.am

@@ -38,4 +38,5 @@ EXTRA_DIST += \
 	expander.ui expander.txt \
 	assistant.ui assistant.txt \
 	pickers.ui pickers.txt \
-	lockbutton.ui lockbutton.txt
+	lockbutton.ui lockbutton.txt \
+	spinner.ui spinner.txt

tests/a11y/spinner.txt

@@ -0,0 +1,22 @@
+window1
+  "window"
+  index: 0
+  state: enabled resizable sensitive showing visible
+  toolkit: gail
+  <AtkComponent>
+  layer: window
+  alpha: 1
+  spinner1
+    "unknown"
+    parent: window1
+    index: 0
+    name: Spinner
+    description: Provides visual indication of progress
+    state: enabled sensitive showing visible
+    toolkit: gail
+    <AtkComponent>
+    layer: widget
+    alpha: 1
+    <AtkImage>
+    image size: 12 x 12
+    image description: (null)

tests/a11y/spinner.ui

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <!-- interface-requires gtk+ 3.0 -->
+  <object class="GtkWindow" id="window1">
+    <property name="can_focus">False</property>
+    <property name="type">popup</property>
+    <child>
+      <object class="GtkSpinner" id="spinner1">
+        <property name="visible">True</property>
+        <property name="active">True</property>
+      </object>
+    </child>
+  </object>
+</interface>