Fix new HTML test type when using dart2dart compiler.

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 0689ad78a3273a0888222e1e5b20156b15ceb731..ae57aee054d9dbf55021ff14d7d8b4dad141240f 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -1416,9 +1416,13 @@ class StandardTestSuite extends TestSuite {
           new File.fromUri(copiedScript).writeAsStringSync(
               new File.fromUri(script).readAsStringSync());
         } else {
+          var destination = copiedScript.toFilePath();
+          if (compileToJS) {
+            destination = destination.replaceFirst(dartExtension, '.js');
+          }
           commands.add(_compileCommand(
               script.toFilePath(),
-              copiedScript.toFilePath().replaceFirst(dartExtension, '.js'),
+              destination,
               compiler,
               tempDir,
               info.optionsFromFile));