Fix issue 2625.

tools/testing/dart/test_runner.dart

Index: tools/testing/dart/test_runner.dart
===================================================================
--- tools/testing/dart/test_runner.dart	(revision 6698)
+++ tools/testing/dart/test_runner.dart	(working copy)
@@ -548,7 +548,7 @@
     new TestOutput.fromCase(testCase, exitCode, timedOut, stdout,
                             stderr, new Date.now().difference(startTime));
     timeoutTimer.cancel();
-    if (testCase.output.unexpectedOutput && testCase.configuration['verbose']) {
+    if (testCase.output.unexpectedOutput && processQueue._verbose) {
       print(testCase.displayName);
       for (var line in testCase.output.stderr) print(line);
       for (var line in testCase.output.stdout) print(line);