Make sure NodeValidator uriAttributes aren't passed as attributes

tests/html/node_validator_important_if_you_suppress_make_the_bug_critical_test.dart

Index: tests/html/node_validator_important_if_you_suppress_make_the_bug_critical_test.dart
diff --git a/tests/html/node_validator_important_if_you_suppress_make_the_bug_critical_test.dart b/tests/html/node_validator_important_if_you_suppress_make_the_bug_critical_test.dart
index dfdcbdbddee8890641aa0a3e49e61043111d95c5..e5c5622f79171c1561da1aeedbf5f204104b411d 100644
--- a/tests/html/node_validator_important_if_you_suppress_make_the_bug_critical_test.dart
+++ b/tests/html/node_validator_important_if_you_suppress_make_the_bug_critical_test.dart
@@ -293,6 +293,18 @@ main() {
         '<div></div>');
   });
 
+  group('identify Uri attributes listed as attributes', () {
+    var validator = new NodeValidatorBuilder()
+      ..allowElement(
+          'a',
+          attributes: ['href']);
+  
+    testHtml('reject different-origin link',
+      validator,
+        '<a href="http://www.google.com/foo">Google-Foo</a>',
+        '<a>Google-Foo</a>');
+  });
+
   group('allowTagExtension', () {
      var validator = new NodeValidatorBuilder()
       ..allowTagExtension(