Move promise_test and assert_promise_rejects out of worker-test-harness.

LayoutTests/http/tests/geofencing/apis_not_implemented.html

Index: LayoutTests/http/tests/geofencing/apis_not_implemented.html
diff --git a/LayoutTests/http/tests/geofencing/apis_not_implemented.html b/LayoutTests/http/tests/geofencing/apis_not_implemented.html
index 767a75e74da1c1e7ceb9ea31e8c4c3e4833fe876..5ed7185a633dca85229940b08d79d809237a7981 100644
--- a/LayoutTests/http/tests/geofencing/apis_not_implemented.html
+++ b/LayoutTests/http/tests/geofencing/apis_not_implemented.html
@@ -2,31 +2,9 @@
 <title>Tests that all geofencing methods exposed on a service worker registration always reject.</title>
 <script src="../resources/testharness.js"></script>
 <script src="../resources/testharnessreport.js"></script>
+<script src="../resources/testharness-helpers.js"></script>
 <script src="../serviceworker/resources/test-helpers.js"></script>
 <script>
-// Copied from http/tests/serviceworker/resources/worker-test-harness.js, can be
-// removed once this makes it into testharness.js itself.
-function promise_test(func, name, properties) {
-  properties = properties || {};
-  var test = async_test(name, properties);
-  Promise.resolve(test.step(func, test, test))
-    .then(function() { test.done(); })
-    .catch(test.step_func(function(value) {
-        throw value;
-      }));
-}
-function assert_promise_rejects(promise, code, description) {
-  return promise.then(
-    function() {
-      throw 'assert_promise_rejects: ' + description + ' Promise did not throw.';
-    },
-    function(e) {
-      if (code !== undefined) {
-        assert_throws(code, function() { throw e; }, description);
-      }
-    });
-}
-
 var sw_url = 'resources/emptyworker.js';
 var sw_scope = '/service-worker-scope' + window.location.pathname;