Added DebugLogger to testing scripts.

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
diff --git a/tools/testing/dart/test_suite.dart b/tools/testing/dart/test_suite.dart
index 96299ae2c4c79e8654738c9b67b2a981cfe96f74..898d1d87322bc084d664ba74f1cb747bd4812a66 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -971,8 +971,10 @@ class StandardTestSuite extends TestSuite {
             htmlPath.substring(basePath.length) : htmlPath;
         String fullHtmlPath = htmlPath;
         if (!htmlPath.startsWith('http')) {
-          fullHtmlPath = 'http://127.0.0.1:${serverList[0].port}$htmlPath?'
-              'crossOriginPort=${serverList[1].port}';
+          if (!configuration['list']) {
+            fullHtmlPath = 'http://127.0.0.1:${serverList[0].port}$htmlPath?'
+                'crossOriginPort=${serverList[1].port}';
+          }
         }
         if (info.optionsFromFile['isMultiHtmlTest']
             && subtestNames.length > 0) {
@@ -1714,6 +1716,10 @@ class TestUtils {
     return completer.future;
   }
 
+  static Path debugLogfile() {
+    return new Path(".debug.log");
+  }
+
   static String flakyFileName() {
     // If a flaky test did fail, infos about it (i.e. test name, stdin, stdout)
     // will be written to this file. This is useful for the debugging of