Fix in webui needed from API change in dart:html

lib/src/analyzer.dart

Index: lib/src/analyzer.dart
diff --git a/lib/src/analyzer.dart b/lib/src/analyzer.dart
index 6b9bd1bb1814caa4062f2a81abe9e8351c42b7bf..f6673b91ed5a0ec5b7b1c92a40aa477e1952e2d4 100644
--- a/lib/src/analyzer.dart
+++ b/lib/src/analyzer.dart
@@ -495,7 +495,7 @@ class _Analyzer extends TreeVisitor {
 
     if (name == 'on-key-down' || name == 'on-key-up' ||
         name == 'on-key-press') {
-      value = '\$event = new autogenerated.KeyEvent(\$event); $value';
+      value = '\$event = new autogenerated.KeyEvent.wrap(\$event); $value';
     }
 
     _addEvent(info, toCamelCase(name), (elem) => value);