diff -r 000000000000 -r 6474c204b198 mobile/android/base/tests/robocop_testharness.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/tests/robocop_testharness.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,70 @@
+// -*- Mode: js2; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; -*-
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function sendMessageToJava(message) {
+  SpecialPowers.Services.androidBridge.handleGeckoMessage(message);
+}
+
+function _evalURI(uri, sandbox) {
+  // We explicitly allow Cross-Origin requests, since it is useful for
+  // testing, but we allow relative URLs by maintaining our baseURI.
+  let req = SpecialPowers.Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
+                         .createInstance();
+
+  let baseURI = SpecialPowers.Services.io
+                             .newURI(window.document.baseURI, window.document.characterSet, null);
+  let theURI = SpecialPowers.Services.io
+                            .newURI(uri, window.document.characterSet, baseURI);
+
+  req.open('GET', theURI.spec, false);
+  req.send();
+
+  return SpecialPowers.Cu.evalInSandbox(req.responseText, sandbox, "1.8", uri, 1);
+}
+
+/**
+ * Execute the Javascript file at `uri` in a testing sandbox populated
+ * with the Javascript test harness.
+ *
+ * `uri` should be a String, relative (to window.document.baseURI) or
+ * absolute.
+ *
+ * The Javascript test harness sends all output to Java via
+ * Robocop:JS messages.
+ */
+function testOneFile(uri) {
+  let HEAD_JS = "robocop_head.js";
+
+  // System principal.  This is dangerous, but this is test code that
+  // should only run on developer and build farm machines, and the
+  // test harness needs access to a lot of the Components API,
+  // including Components.stack.  Wrapping Components.stack in
+  // SpecialPowers magic obfuscates stack traces wonderfully,
+  // defeating much of the point of the test harness.
+  let principal = SpecialPowers.Cc["@mozilla.org/systemprincipal;1"]
+                               .createInstance(SpecialPowers.Ci.nsIPrincipal);
+
+  let testScope = SpecialPowers.Cu.Sandbox(principal);
+
+  // Populate test environment with test harness prerequisites.
+  testScope.Components = SpecialPowers.Components;
+  testScope._TEST_FILE = uri;
+
+  // Output from head.js is fed, line by line, to this function.  We
+  // send any such output back to the Java Robocop harness.
+  testScope.dump = function (str) {
+    let message = { type: "Robocop:JS",
+                    innerType: "progress",
+                    message: str,
+                  };
+    sendMessageToJava(message);
+  };
+
+  // Populate test environment with test harness.  The symbols defined
+  // above must be present before executing the test harness.
+  _evalURI(HEAD_JS, testScope);
+
+  return _evalURI(uri, testScope);
+}