Copy lib/dom tests that use dart:html to lib/html.

tests/dom/callbacks_test.dart

Index: tests/dom/callbacks_test.dart
diff --git a/tests/dom/callbacks_test.dart b/tests/dom/callbacks_test.dart
deleted file mode 100644
index cc8b2c961d2bbbec5cc838f18b009266f6b523df..0000000000000000000000000000000000000000
--- a/tests/dom/callbacks_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-#library('CallbacksTest');
-#import('../../lib/unittest/unittest.dart');
-#import('../../lib/unittest/html_config.dart');
-#import('dart:html');
-
-main() {
-  useHtmlConfiguration();
-  test('RequestAnimationFrameCallback', () {
-    window.webkitRequestAnimationFrame((int time) => false);
-  });
-}