diff -r 000000000000 -r 6474c204b198 dom/base/test/file_url.jsm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/base/test/file_url.jsm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,18 @@
+this.EXPORTED_SYMBOLS = ['checkFromJSM'];
+
+this.checkFromJSM = function checkFromJSM(ok, is) {
+  Components.utils.importGlobalProperties(['URL']);
+
+  var url = new URL('http://www.example.com');
+  is(url.href, "http://www.example.com/", "JSM should have URL");
+
+  var url2 = new URL('/foobar', url);
+  is(url2.href, "http://www.example.com/foobar", "JSM should have URL - based on another URL");
+
+  var blob = new Blob(['a']);
+  var url = URL.createObjectURL(blob);
+  ok(url, "URL is created!");
+
+  URL.revokeObjectURL(url);
+  ok(true, "URL is revoked");
+}