Fix some type and logical errors in test.dart, found by the Dart editor.

tools/testing/dart/test_progress.dart

Index: tools/testing/dart/test_progress.dart
diff --git a/tools/testing/dart/test_progress.dart b/tools/testing/dart/test_progress.dart
index df4daaf4a43ddaea8273098c486d3624812eeb08..7b4a3d1f1f4021886d126f74ec5eccfa01579553 100644
--- a/tools/testing/dart/test_progress.dart
+++ b/tools/testing/dart/test_progress.dart
@@ -5,6 +5,7 @@
 #library("test_progress");
 
 #import("dart:io");
+#import("dart:builtin");
 #import("test_runner.dart");
 #import("test_suite.dart");
 
@@ -198,6 +199,8 @@ class SilentProgressIndicator extends ProgressIndicator {
   void testAdded() { }
   void start(TestCase test) { }
   void done(TestCase test) { }
+  void _printStartProgress(TestCase test) { }
+  void _printDoneProgress(TestCase test) { }
   void allTestsKnown() { }
   void allDone() {
     exit(0);