Added support for logging the output of failed flaky tests.

tools/test-runtime.dart

Index: tools/test-runtime.dart
diff --git a/tools/test-runtime.dart b/tools/test-runtime.dart
index b9663ffe0cab54ad2933118a25332976f3ff5e89..05aac408f812c5963e35404bcfcec82711c2c8c2 100755
--- a/tools/test-runtime.dart
+++ b/tools/test-runtime.dart
@@ -50,7 +50,13 @@ main() {
   var verbose = firstConf['verbose'];
   var printTiming = firstConf['time'];
   var listTests = firstConf['list'];
-
+  
+  if (!firstConf['append_flaky_log'])  {
+    var file = new File(TestUtils.flakyFileName());

[ahe, 2012/11/09 10:35:02]

Should flakyFileName be a getter?

+    if (file.existsSync()) {
+      file.deleteSync();
+    }
+  }
   // Print the configurations being run by this execution of
   // test.dart. However, don't do it if the silent progress indicator
   // is used. This is only needed because of the junit tests.