record that Gamepad.buttons creates GamepadButtons

tests/html/gamepad_test.dart

Index: tests/html/gamepad_test.dart
diff --git a/tests/html/client_rect_test.dart b/tests/html/gamepad_test.dart
similarity index 60%
copy from tests/html/client_rect_test.dart
copy to tests/html/gamepad_test.dart
index b9c9bb547582979bf494e4b6ada696c8c64be29d..6bbef593d8df0537318ebcdb2d33d5c58ac55c9a 100644
--- a/tests/html/client_rect_test.dart
+++ b/tests/html/gamepad_test.dart
@@ -1,12 +1,10 @@
-library ClientRectTest;
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
 import 'dart:html';
 
 main() {
-
-  var isRectList =
-      predicate((x) => x is List<Rectangle>, 'is a List<Rectangle>');
+  var isGamepadList =
+      predicate((x) => x is List<Gamepad>, 'is a List<Gamepad>');
 
   insertTestDiv() {
     var element = new Element.tag('div');
@@ -21,10 +19,14 @@ main() {
 
   useHtmlConfiguration();
 
-   test("ClientRectList test", () {
+  test("getGamepads", () {
     insertTestDiv();
-    var range = new Range();
-    var rects = range.getClientRects();
-    expect(rects, isRectList);
+    var gamepads = window.navigator.getGamepads();
+    expect(gamepads, isGamepadList);
+    for (var gamepad in gamepads) {
+      if (gamepad != null) {
+        expect(gamepad.id, isNotNull);
+      }
+    }
   });
 }