Add a calendar testcase

tests/a11y/Makefile.am

@@ -41,4 +41,5 @@ EXTRA_DIST += \
 	lockbutton.ui lockbutton.txt \
 	spinner.ui spinner.txt \
 	progress.ui progress.txt \
-	infobar.ui infobar.txt
+	infobar.ui infobar.txt \
+	calendar.ui calendar.txt

tests/a11y/calendar.txt

@@ -0,0 +1,17 @@
+window1
+  "window"
+  index: 0
+  state: enabled resizable sensitive showing visible
+  toolkit: gail
+  <AtkComponent>
+  layer: window
+  alpha: 1
+  calendar1
+    "calendar"
+    parent: window1
+    index: 0
+    state: enabled focusable sensitive showing visible
+    toolkit: gail
+    <AtkComponent>
+    layer: widget
+    alpha: 1

tests/a11y/calendar.ui

@@ -0,0 +1,16 @@
+<?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="GtkCalendar" id="calendar1">
+        <property name="visible">True</property>
+        <property name="day">1</property>
+        <property name="month">2</property>
+        <property name="year">1970</property>
+      </object>
+    </child>
+  </object>
+</interface>