diff -r 000000000000 -r 6474c204b198 dom/system/gonk/tests/marionette/head.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/system/gonk/tests/marionette/head.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,134 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+MARIONETTE_CONTEXT = "chrome";
+
+let Promise = Cu.import("resource://gre/modules/Promise.jsm").Promise;
+
+/**
+ * Wrap DOMRequest onsuccess/onerror events to Promise resolve/reject.
+ *
+ * Fulfill params: A DOMEvent.
+ * Reject params: A DOMEvent.
+ *
+ * @param aRequest
+ *        A DOMRequest instance.
+ *
+ * @return A deferred promise.
+ */
+function wrapDomRequestAsPromise(aRequest) {
+  let deferred = Promise.defer();
+
+  ok(aRequest instanceof DOMRequest,
+     "aRequest is instanceof " + aRequest.constructor);
+
+  aRequest.addEventListener("success", function(aEvent) {
+    deferred.resolve(aEvent);
+  });
+  aRequest.addEventListener("error", function(aEvent) {
+    deferred.reject(aEvent);
+  });
+
+  return deferred.promise;
+}
+
+/**
+ * Get mozSettings value specified by @aKey.
+ *
+ * Resolve if that mozSettings value is retrieved successfully, reject
+ * otherwise.
+ *
+ * Fulfill params: The corresponding mozSettings value of the key.
+ * Reject params: (none)
+ *
+ * @param aKey
+ *        A string.
+ * @param aAllowError [optional]
+ *        A boolean value.  If set to true, an error response won't be treated
+ *        as test failure.  Default: false.
+ *
+ * @return A deferred promise.
+ */
+function getSettings(aKey, aAllowError) {
+  let request = window.navigator.mozSettings.createLock().get(aKey);
+  return wrapDomRequestAsPromise(request)
+    .then(function resolve(aEvent) {
+      log("getSettings(" + aKey + ") - success");
+      return aEvent.target.result[aKey];
+    }, function reject(aEvent) {
+      ok(aAllowError, "getSettings(" + aKey + ") - error");
+    });
+}
+
+/**
+ * Set mozSettings values.
+ *
+ * Resolve if that mozSettings value is set successfully, reject otherwise.
+ *
+ * Fulfill params: (none)
+ * Reject params: (none)
+ *
+ * @param aKey
+ *        A string key.
+ * @param aValue
+ *        An object value.
+ * @param aAllowError [optional]
+ *        A boolean value.  If set to true, an error response won't be treated
+ *        as test failure.  Default: false.
+ *
+ * @return A deferred promise.
+ */
+function setSettings(aKey, aValue, aAllowError) {
+  let settings = {};
+  settings[aKey] = aValue;
+  let request = window.navigator.mozSettings.createLock().set(settings);
+  return wrapDomRequestAsPromise(request)
+    .then(function resolve() {
+      log("setSettings(" + JSON.stringify(settings) + ") - success");
+    }, function reject() {
+      ok(aAllowError, "setSettings(" + JSON.stringify(settings) + ") - error");
+    });
+}
+
+/**
+ * Wait for observer event.
+ *
+ * Resolve if that topic event occurs.  Never reject.
+ *
+ * Fulfill params: the subject passed.
+ *
+ * @param aTopic
+ *        A string topic name.
+ *
+ * @return A deferred promise.
+ */
+function waitForObserverEvent(aTopic) {
+  let obs = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);
+  let deferred = Promise.defer();
+
+  obs.addObserver(function observer(subject, topic, data) {
+    if (topic === aTopic) {
+      obs.removeObserver(observer, aTopic);
+      deferred.resolve(subject);
+    }
+  }, aTopic, false);
+
+  return deferred.promise;
+}
+
+/**
+ * Basic test routine helper.
+ *
+ * This helper does nothing but clean-ups.
+ *
+ * @param aTestCaseMain
+ *        A function that takes no parameter.
+ */
+function startTestBase(aTestCaseMain) {
+  Promise.resolve()
+    .then(aTestCaseMain)
+    .then(finish, function() {
+      ok(false, 'promise rejects during test.');
+      finish();
+    });
+}