Enable frong testing components.

tools/testing/dart/test_progress.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library("test_progress");
 
 #import("test_runner.dart");
 
 class ProgressIndicator {
   ProgressIndicator() : _startTime = new Date.now();
@@ skipping 36 matching lines @@
   }
 
   String _timeString() {
     Duration d = (new Date.now()).difference(_startTime);
     var min = d.inMinutes;
     var sec = d.inSeconds;
     return '${_padTime(min)}:${_padTime(sec)}';
   }
 
   void _printFailureOutput(TestCase test) {
-    print('FAILED: ${test.displayName}');
+    print('\nFAILED: ${test.displayName}');
+    StringBuffer expected = new StringBuffer();
+    expected.add('Expected: ');
+    for (var expectation in test.expectedOutcomes) {
+      expected.add('$expectation ');
+    }
+    print(expected.toString());
+    print('Actual: ${test.output.result}');
     if (!test.output.stdout.isEmpty()) {
       print('\nstdout:');
       test.output.stdout.forEach((s) => print(s));
     }
     if (!test.output.stderr.isEmpty()) {
       print('\nstderr:');
       test.output.stderr.forEach((s) => print(s));
     }
     print('\nCommand line: ${test.commandLine}');
   }
 
   int _completedTests() => _passedTests + _failedTests;
 
   int _foundTests = 0;
   int _passedTests = 0;
   int _failedTests = 0;
   Date _startTime;
 }
 
 
 class CompactProgressIndicator extends ProgressIndicator {
   void _printProgress() {
     var percent = ((_completedTests() / _foundTests) * 100).floor().toString();
     var percentPadded = _pad(percent, 5);
     var passedPadded = _pad(_passedTests.toString(), 5);
     var failedPadded = _pad(_failedTests.toString(), 5);
     var progressLine =
-      '[${_timeString()} | $percentPadded% | +$passedPadded | -$failedPadded]';
-    // TODO(ager): Instead of using print we should write this to
-    // stdout and use \r to reuse the same line.
-    print(progressLine);
+        '\r[${_timeString()} | $percentPadded% | ' +
+        '+$passedPadded | -$failedPadded]';
+    stdout.write(progressLine.charCodes());
   }
 }