Reduce test.dart memory usage.

tools/testing/dart/test_progress.dart

 // Copyright (c) 2013, 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 "dart:async";
 import "dart:io";
 import "dart:io" as io;
 import "dart:convert" show JSON;
@@ skipping 508 matching lines @@
           print(line);
         }
         print('');
 
         print(_buildSummaryEnd(_failedTests));
       }
     }
   }
 }
 
+class DeleteTestCaseOutput extends EventListener {
+  void done(TestCase test) {
+    for (CommandOutputImpl output in test.commandOutputs.values) {
+      output.stdout = null;
+      output.stderr = null;
+    }
+  }

[kustermann, 2014/04/11 15:17:37]

I think you shouldn't do that. If two test cases (e.g. dart2js-ff and
dart2js-chrome) share the same compilation command, and one of them finished,
you can't delete the output: If the other one fails and you print the output,
the compilation output will be null!

[Bill Hesse, 2014/04/23 14:52:41]

Removing the code that deletes test output.  Leaving just the minor changes in
this cl.

+}
+
 class ProgressIndicator extends EventListener {
   ProgressIndicator(this._startTime);
 
 
   void testAdded() { _foundTests++; }
 
   void done(TestCase test) {
     if (test.unexpectedOutput) {
       _failedTests++;
     } else {
@@ skipping 122 matching lines @@
       return new VerboseProgressIndicator(startTime);
     case 'status':
       return new ProgressIndicator(startTime);
     case 'buildbot':
       return new BuildbotProgressIndicator(startTime);
     default:
       assert(false);
       break;
   }
 }