diff -r 000000000000 -r 6474c204b198 extensions/cookie/test/file_testcommon.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/extensions/cookie/test/file_testcommon.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,76 @@
+var gExpectedCookies;
+var gExpectedLoads;
+
+var gPopup;
+
+var gLoads = 0;
+
+function setupTest(uri, cookies, loads) {
+  SimpleTest.waitForExplicitFinish();
+
+  SpecialPowers.Cc["@mozilla.org/preferences-service;1"]
+               .getService(SpecialPowers.Ci.nsIPrefBranch)
+               .setIntPref("network.cookie.cookieBehavior", 1);
+
+  var cs = SpecialPowers.Cc["@mozilla.org/cookiemanager;1"]
+                        .getService(SpecialPowers.Ci.nsICookieManager2);
+  cs.removeAll();
+
+  gExpectedCookies = cookies;
+  gExpectedLoads = loads;
+
+  // Listen for MessageEvents.
+  window.addEventListener("message", messageReceiver, false);
+
+  // load a window which contains an iframe; each will attempt to set
+  // cookies from their respective domains.
+  gPopup = window.open(uri, 'hai', 'width=100,height=100');
+}
+
+function finishTest()
+{
+  SpecialPowers.Cc["@mozilla.org/preferences-service;1"]
+               .getService(SpecialPowers.Ci.nsIPrefBranch)
+               .clearUserPref("network.cookie.cookieBehavior");
+
+  SimpleTest.finish();
+}
+
+/** Receives MessageEvents to this window. */
+// Count and check loads.
+function messageReceiver(evt)
+{
+  is(evt.data, "message", "message data received from popup");
+  if (evt.data != "message") {
+    gPopup.close();
+    window.removeEventListener("message", messageReceiver, false);
+
+    finishTest();
+    return;
+  }
+
+  // only run the test when all our children are done loading & setting cookies
+  if (++gLoads == gExpectedLoads) {
+    gPopup.close();
+    window.removeEventListener("message", messageReceiver, false);
+
+    runTest();
+  }
+}
+
+// runTest() is run by messageReceiver().
+// Count and check cookies.
+function runTest() {
+  // set a cookie from a domain of "localhost"
+  document.cookie = "oh=hai";
+
+  var cs = SpecialPowers.Cc["@mozilla.org/cookiemanager;1"]
+                        .getService(SpecialPowers.Ci.nsICookieManager);
+  var count = 0;
+  for(var list = cs.enumerator; list.hasMoreElements(); list.getNext())
+    ++count;
+  is(count, gExpectedCookies, "total number of cookies");
+  cs.removeAll();
+
+  finishTest();
+}