Unify multiple sequential_promise_test definitions.

LayoutTests/http/tests/navigatorconnect/resources/test-helpers.js

Index: LayoutTests/http/tests/navigatorconnect/resources/test-helpers.js
diff --git a/LayoutTests/http/tests/navigatorconnect/resources/test-helpers.js b/LayoutTests/http/tests/navigatorconnect/resources/test-helpers.js
index 9c40755d8c447f05997677e1b3a6d9b88f5f926a..66d40dab74c4b406d69905892d4c83c125d30ca1 100644
--- a/LayoutTests/http/tests/navigatorconnect/resources/test-helpers.js
+++ b/LayoutTests/http/tests/navigatorconnect/resources/test-helpers.js
@@ -90,19 +90,3 @@ function wrap_in_port(maybe_port) {
     }
   );
 }
-
-var promise_tests = Promise.resolve();
-// Helper function to run promise tests one after the other.
-// TODO(ortuno): Remove once https://github.com/w3c/testharness.js/pull/115/files
-// gets through.
-function sequential_promise_test(func, name) {
-  var test = async_test(name);
-  promise_tests = promise_tests.then(function() {
-    return test.step(func, test, test);
-  }).then(function() {
-    test.done();
-  }).catch(test.step_func(function(value) {
-    // step_func catches the error again so the error doesn't propagate.
-    throw value;
-  }));
-}