Add print closure.

lib/dom/src/native_DOMImplementation.dart

Index: lib/dom/src/native_DOMImplementation.dart
diff --git a/lib/dom/src/native_DOMImplementation.dart b/lib/dom/src/native_DOMImplementation.dart
index 61f9a4b50299a661df69efc8467de21fe9f8395f..d6a79b975626577fe7f591f911ddddddf192a996 100644
--- a/lib/dom/src/native_DOMImplementation.dart
+++ b/lib/dom/src/native_DOMImplementation.dart
@@ -32,12 +32,11 @@ class _Utils {
   }
 
   static window() native "Utils_window";
+  static print(String message) native "Utils_print";
   static SendPort spawnDomFunctionImpl(Function topLevelFunction) native "Utils_spawnDomFunction";
   static int _getNewIsolateId() native "Utils_getNewIsolateId";
 }
 
-Utils_print(String message) native "Utils_print";
-
 class _NPObject extends NativeFieldWrapperClass1 {
   _NPObject();
   static _NPObject retrieve(String key) native "NPObject_retrieve";
@@ -105,3 +104,11 @@ class _DOMStringMapImpl extends NativeFieldWrapperClass1 implements Map<String,
   int get length() => Maps.length(this);
   bool isEmpty() => Maps.isEmpty(this);
 }
+
+get _printClosure => (s) {
+  try {
+    window.console.log(s);
+  } on Dynamic catch(_) {
+    _Utils.print(s);
+  }
+};