Rename Date to DateTime.

tests/standalone/io/http_connection_close_test.dart

Index: tests/standalone/io/http_connection_close_test.dart
diff --git a/tests/standalone/io/http_connection_close_test.dart b/tests/standalone/io/http_connection_close_test.dart
index 67106e61a403b307af16bc0870440c7e102cff82..4ff27a2f23e3402846ade2a2d1a29901c153b680 100644
--- a/tests/standalone/io/http_connection_close_test.dart
+++ b/tests/standalone/io/http_connection_close_test.dart
@@ -52,7 +52,7 @@ void testStreamResponse() {
   server.listen("127.0.0.1", 0, backlog: 5);
   server.defaultRequestHandler = (var request, var response) {
     timer = new Timer.repeating(10, (_) {
-      Date now = new Date.now();
+      DateTime now = new DateTime.now();
       try {
         response.outputStream.writeString(
             'data:${now.millisecondsSinceEpoch}\n\n');