Get rid of Dynamic.

lib/html/src/native_DOMImplementation.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class _Utils {
   static List convertToList(List list) {
     // FIXME: [possible optimization]: do not copy the array if Dart_IsArray is fine w/ it.
     final length = list.length;
     List result = new List(length);
     result.setRange(0, length, list);
@@ skipping 91 matching lines @@
   void forEach(void f(String key, String value)) => Maps.forEach(this, f);
   Collection<String> getKeys() native "DOMStringMap_getKeys_Callback";
   Collection<String> getValues() => Maps.getValues(this);
   int get length => Maps.length(this);
   bool isEmpty() => Maps.isEmpty(this);
 }
 
 get _printClosure => (s) {
   try {
     window.console.log(s);
-  } on Dynamic catch(_) {
+  } catch (_) {
     _Utils.print(s);
   }
 };