Add python wrapper for test.dart.

tools/testing/dart/test_options.dart

Index: tools/testing/dart/test_options.dart
diff --git a/tools/testing/dart/test_options.dart b/tools/testing/dart/test_options.dart
index 0d6e72104c2ba26b03e0ae059a0104ef2aabc10f..64b62127053b35baad128b72494eccd23ca45a1b 100644
--- a/tools/testing/dart/test_options.dart
+++ b/tools/testing/dart/test_options.dart
@@ -294,8 +294,9 @@ is 'dart file.dart' and you specify special command
       configuration['special-command'] = 'python -u $valgrind @';
     }
 
-    // Use verbose progress indication for verbose output.
-    if (configuration['verbose']) {
+    // Use verbose progress indication for verbose output unless buildbot progress

[Bill Hesse, 2012/01/04 15:11:08]

Is this line too long?

+    // indication is requested.
+    if (configuration['verbose'] && configuration['progress'] != 'buildbot') {
       configuration['progress'] = 'verbose';
     }