shell: Use a busy cursor animation for unresponsive surfaces
diff --git a/protocol/desktop-shell.xml b/protocol/desktop-shell.xml
index d2bb3eb..a9c181c 100644
--- a/protocol/desktop-shell.xml
+++ b/protocol/desktop-shell.xml
@@ -23,6 +23,10 @@
 
     <request name="unlock"/>
 
+    <request name="set_busy_surface">
+      <arg name="surface" type="object" interface="wl_surface"/>
+    </request>
+
     <!-- We'll fold most of wl_shell into this interface and then
          they'll share the configure event.  -->
     <event name="configure">