Attempting to fix XHR test.

tests/html/xhr_test.dart

Index: tests/html/xhr_test.dart
diff --git a/tests/html/xhr_test.dart b/tests/html/xhr_test.dart
index 8ddae007792bc1b9857ea311bda4c529ec938d0a..7c2f863519a39c3b50580b55af69785904ac89be 100644
--- a/tests/html/xhr_test.dart
+++ b/tests/html/xhr_test.dart
@@ -18,7 +18,11 @@ void fail(message) {
 
 main() {
   useHtmlIndividualConfiguration();
-  var url = "/root_dart/tests/html/xhr_cross_origin_data.txt";
+  // Cache blocker is a workaround for:
+  // https://code.google.com/p/dart/issues/detail?id=11834
+  var cacheBlocker = new DateTime.now().millisecondsSinceEpoch;
+  var url = '/root_dart/tests/html/xhr_cross_origin_data.txt?'
+      'cacheBlock=$cacheBlocker';
 
   void validate200Response(xhr) {
     expect(xhr.status, equals(200));