Uncomment and clean up all_the_rest.dart tests.

pkg/analyzer/lib/src/generated/html.dart

Index: pkg/analyzer/lib/src/generated/html.dart
diff --git a/pkg/analyzer/lib/src/generated/html.dart b/pkg/analyzer/lib/src/generated/html.dart
index b55947734d40f442401e6fd681078db1872f72d1..457df54a162f27443e25881e91d7ae2bcc1d83d4 100644
--- a/pkg/analyzer/lib/src/generated/html.dart
+++ b/pkg/analyzer/lib/src/generated/html.dart
@@ -1965,6 +1965,7 @@ class XmlTagNode extends XmlNode {
       return content;
     }
     JavaStringBuilder buffer = new JavaStringBuilder();
+    buffer.append(content);
     while (!identical(token, contentEnd)) {
       buffer.append(token.lexeme);
       token = token.next;