remove node.js dependency by running the frog compiler in

tools/testing/dart/test_runner.dart

Index: tools/testing/dart/test_runner.dart
diff --git a/tools/testing/dart/test_runner.dart b/tools/testing/dart/test_runner.dart
index feaea15d3dc62998b9c9dbc2169e036d68657360..f9c9c36656656f0b76b34f52127b2f2ff7ed06c8 100644
--- a/tools/testing/dart/test_runner.dart
+++ b/tools/testing/dart/test_runner.dart
@@ -511,7 +511,6 @@ class RunningProcess {
     if (currentStep == totalSteps) { // done with test command
       testComplete(exitCode);
     } else if (exitCode != 0) {
-      stderr.add('test.dart: Compilation failed$suffix, exit code $exitCode\n');
       testComplete(exitCode);
     } else {
       stderr.add('test.dart: Compilion finished $suffix\n');