Advance html5lib to newest breaking changes in core: getKeys -> keys, etc

test/parser_test.dart

Index: test/parser_test.dart
diff --git a/test/parser_test.dart b/test/parser_test.dart
index 69a1355990f04393cd5ff54dec23e589756ee57e..88889a4c14d664296e65b920333e10a87f9799e5 100644
--- a/test/parser_test.dart
+++ b/test/parser_test.dart
@@ -83,7 +83,7 @@ void main() {
             errors = errors.split("\n");
           }
 
-          for (var treeCtor in treeTypes.getValues()) {
+          for (var treeCtor in treeTypes.values) {
             for (var namespaceHTMLElements in const [false, true]) {
               test(input, () {
                 runParserTest(testName, innerHTML, input, expected, errors,