Write our JS blobs for handling native classes in Dart.

frog/leg/lib/js_helper.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.
 
 #library('js_helper');
 
 #import('coreimpl.dart');
 
 #source('constant_map.dart');
 #source('date_helper.dart');
+#source('native_helper.dart');
 #source('regexp_helper.dart');
 #source('string_helper.dart');
 
 /**
  * Returns true if both arguments are numbers.
  *
  * If only the first argument is a number, an
  * [IllegalArgumentException] with the other argument is thrown.
  */
 bool checkNumbers(var a, var b) {
@@ skipping 1151 matching lines @@
 // TODO(ahe): Dynamic may be overridden.
 builtin$get$dynamic(receiver) => receiver;
 
 /**
  * Called by generated code to capture the stacktrace before throwing
  * an exception.
  */
 captureStackTrace(ex) {
   var jsError = JS('Object', @'new Error()');
   JS('void', @'#.dartException = #', jsError, ex);
-  JS('void', @'''#.toString = #''', jsError, toStringWrapper);
+  JS('void', @'''#.toString = #''', jsError, JS_TO_CLOSURE(toStringWrapper));
   return jsError;
 }
 
 /**
  * This method is installed as JavaScript toString method on exception
  * objects in [captureStackTrace]. So JavaScript 'this' binds to an
  * instance of JavaScript Error to which we have added a property
  * 'dartException' which holds a Dart object.
  */
 toStringWrapper() => JS('Object', @'this.dartException').toString();
@@ skipping 110 matching lines @@
  * closure when the Dart closure is passed to the DOM.
  */
 convertDartClosureToJS(closure) {
   if (closure === null) return null;
   var function = JS('var', @'#.$identity', closure);
   if (JS('bool', @'!!#', function)) return function;
 
   function = JS("var", @"""function() {
     return #(#, #, arguments.length, arguments[0], arguments[1]);
   }""",
-  invokeClosure,
+  JS_TO_CLOSURE(invokeClosure),
   closure,
   JS_CURRENT_ISOLATE());
 
   JS('void', @'#.$identity = #', closure, function);
   return function;
 }
 
 /**
  * Super class for Dart closures.
  */
@@ skipping 32 matching lines @@
 }
 
 /**
  * Represents the type of Null. The compiler treats this specially.
  */
 class Null {
   factory Null() {
     throw UnsupportedOperationException('new Null()');
   }
 }