diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/shell-watchdog.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/shell-watchdog.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,16 @@
+// |jit-test| exitstatus: 6;
+
+/* This test will loop infinitely if the shell watchdog
+   fails to kick in. */
+
+timeout(0.1);
+var start = new Date();
+
+while (true) {
+    var end = new Date();
+    var duration = (end.getTime() - start.getTime()) / 1000;
+    if (duration > 1) {
+        print("tick");
+        start = new Date();
+    }
+}