diff -r 000000000000 -r 6474c204b198 dom/workers/test/test_xhr_system.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/workers/test/test_xhr_system.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+function ok(what, msg) {
+  postMessage({ event: msg, test: 'ok', a: what });
+}
+
+function is(a, b, msg) {
+  postMessage({ event: msg, test: 'is', a: a, b: b });
+}
+
+self.onmessage = function onmessage(event) {
+
+  // An XHR with system privileges will be able to do cross-site calls.
+
+  const TEST_URL = "http://example.com/tests/content/base/test/test_XHR_system.html";
+  is(location.hostname, "mochi.test", "hostname should be mochi.test");
+
+  var xhr = new XMLHttpRequest({mozSystem: true});
+  is(xhr.mozSystem, true, ".mozSystem == true");
+  xhr.open("GET", TEST_URL);
+  xhr.onload = function onload() {
+    is(xhr.status, 200);
+    ok(xhr.responseText != null);
+    ok(xhr.responseText.length);
+    postMessage({test: "finish"});
+  };
+  xhr.onerror = function onerror() {
+    ok(false, "Got an error event!");
+    postMessage({test: "finish"});
+  }
+  xhr.send();
+};