diff --git a/pkg/dev_compiler/lib/runtime/dart_sdk.js b/pkg/dev_compiler/lib/runtime/dart_sdk.js
index 67c5d7ae92bb..99b1c89f7514 100644
--- a/pkg/dev_compiler/lib/runtime/dart_sdk.js
+++ b/pkg/dev_compiler/lib/runtime/dart_sdk.js
@@ -20,6 +20,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
   const core = Object.create(null);
   const isolate = Object.create(null);
   const js = Object.create(null);
+  const js_util = Object.create(null);
   const math = Object.create(null);
   const mirrors = Object.create(null);
   const typed_data = Object.create(null);
@@ -629,6 +630,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
   let dynamicAnddynamicAndFnToObject = () => (dynamicAnddynamicAndFnToObject = dart.constFn(dart.definiteFunctionType(core.Object, [dart.dynamic, dart.dynamic, dynamicTodynamic()])))();
   let FToF = () => (FToF = dart.constFn(dart.definiteFunctionType(F => [F, [F]])))();
   let FunctionToFunction = () => (FunctionToFunction = dart.constFn(dart.definiteFunctionType(core.Function, [core.Function])))();
+  let FunctionAndListTodynamic = () => (FunctionAndListTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [core.Function, core.List])))();
   let TAndTToT = () => (TAndTToT = dart.constFn(dart.definiteFunctionType(T => [T, [T, T]])))();
   let TAndTToT$ = () => (TAndTToT$ = dart.constFn(dart.definiteFunctionType(T => [T, [T, T]])))();
   let numAndnumTodouble = () => (numAndnumTodouble = dart.constFn(dart.definiteFunctionType(core.double, [core.num, core.num])))();
@@ -33773,6 +33775,109 @@ dart_library.library('dart_sdk', null, /* Imports */[
     return ret;
   };
   dart.fn(js.allowInteropCaptureThis, FunctionToFunction());
+  js_util.jsify = function(object) {
+    if (!core.Map.is(object) && !core.Iterable.is(object)) {
+      dart.throw(new core.ArgumentError("object must be a Map or Iterable"));
+    }
+    return js_util._convertDataTree(object);
+  };
+  dart.fn(js_util.jsify, dynamicTodynamic$());
+  js_util._convertDataTree = function(data) {
+    let _convertedObjects = collection.HashMap.identity();
+    function _convert(o) {
+      if (dart.test(_convertedObjects.containsKey(o))) {
+        return _convertedObjects.get(o);
+      }
+      if (core.Map.is(o)) {
+        let convertedMap = {};
+        _convertedObjects.set(o, convertedMap);
+        for (let key of o[dartx.keys]) {
+          convertedMap[key] = _convert(o[dartx.get](key));
+        }
+        return convertedMap;
+      } else if (core.Iterable.is(o)) {
+        let convertedList = [];
+        _convertedObjects.set(o, convertedList);
+        convertedList[dartx.addAll](o[dartx.map](dart.dynamic)(_convert));
+        return convertedList;
+      } else {
+        return o;
+      }
+    }
+    dart.fn(_convert, dynamicTodynamic$());
+    return _convert(data);
+  };
+  dart.fn(js_util._convertDataTree, dynamicTodynamic$());
+  js_util.newObject = function() {
+    return {};
+  };
+  dart.fn(js_util.newObject, VoidTodynamic$());
+  js_util.hasProperty = function(o, name) {
+    return name in o;
+  };
+  dart.fn(js_util.hasProperty, dynamicAnddynamicTodynamic$());
+  js_util.getProperty = function(o, name) {
+    return o[name];
+  };
+  dart.fn(js_util.getProperty, dynamicAnddynamicTodynamic$());
+  js_util.setProperty = function(o, name, value) {
+    return o[name] = value;
+  };
+  dart.fn(js_util.setProperty, dynamicAnddynamicAnddynamicTodynamic());
+  js_util.callMethod = function(o, method, args) {
+    return o[method].apply(o, args);
+  };
+  dart.fn(js_util.callMethod, dynamicAndStringAndListTodynamic());
+  js_util.instanceof = function(o, type) {
+    return o instanceof type;
+  };
+  dart.fn(js_util.instanceof, dynamicAndFunctionTodynamic());
+  js_util.callConstructor = function(constr, arguments$) {
+    if (arguments$ == null) {
+      return new constr();
+    }
+    if (arguments$ instanceof Array) {
+      let argumentCount = arguments$.length;
+      switch (argumentCount) {
+        case 0:
+        {
+          return new constr();
+        }
+        case 1:
+        {
+          let arg0 = arguments$[0];
+          return new constr(arg0);
+        }
+        case 2:
+        {
+          let arg0 = arguments$[0];
+          let arg1 = arguments$[1];
+          return new constr(arg0, arg1);
+        }
+        case 3:
+        {
+          let arg0 = arguments$[0];
+          let arg1 = arguments$[1];
+          let arg2 = arguments$[2];
+          return new constr(arg0, arg1, arg2);
+        }
+        case 4:
+        {
+          let arg0 = arguments$[0];
+          let arg1 = arguments$[1];
+          let arg2 = arguments$[2];
+          let arg3 = arguments$[3];
+          return new constr(arg0, arg1, arg2, arg3);
+        }
+      }
+    }
+    let args = [null];
+    args[dartx.addAll](arguments$);
+    let factoryFunction = constr.bind.apply(constr, args);
+    String(factoryFunction);
+    return new factoryFunction();
+  };
+  dart.fn(js_util.callConstructor, FunctionAndListTodynamic());
   math.E = 2.718281828459045;
   math.LN10 = 2.302585092994046;
   math.LN2 = 0.6931471805599453;
@@ -84098,6 +84203,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
   exports.core = core;
   exports.isolate = isolate;
   exports.js = js;
+  exports.js_util = js_util;
   exports.math = math;
   exports.mirrors = mirrors;
   exports.typed_data = typed_data;
diff --git a/pkg/dev_compiler/test/browser/language_tests.js b/pkg/dev_compiler/test/browser/language_tests.js
index c92dfd853382..026b5f5adb12 100644
--- a/pkg/dev_compiler/test/browser/language_tests.js
+++ b/pkg/dev_compiler/test/browser/language_tests.js
@@ -2629,6 +2629,7 @@
       'js_function_getter_trust_types_test': 'unittest',
       'js_interop_1_test': 'unittest',
       'js_test': 'unittest',
+      'js_util_test': 'unittest',
       'js_typed_interop_anonymous2_exp_test': 'unittest',
       'js_typed_interop_anonymous2_test': 'unittest',
       'js_typed_interop_anonymous_exp_test': 'unittest',
diff --git a/pkg/dev_compiler/test/codegen/lib/html/js_util_test.dart b/pkg/dev_compiler/test/codegen/lib/html/js_util_test.dart
new file mode 100644
index 000000000000..b0130b24d6b6
--- /dev/null
+++ b/pkg/dev_compiler/test/codegen/lib/html/js_util_test.dart
@@ -0,0 +1,347 @@
+// Copyright (c) 2013, 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.
+
+@JS()
+library js_native_test;
+
+import 'dart:async';
+import 'dart:html';
+import 'dart:typed_data' show ByteBuffer, Int32List;
+import 'dart:indexed_db' show IdbFactory, KeyRange;
+
+import 'package:js/js.dart';
+import 'package:js/js_util.dart' as js_util;
+
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_individual_config.dart';
+
+_injectJs() {
+  final script = new ScriptElement();
+  script.type = 'text/javascript';
+  script.innerHtml = r"""
+var x = 42;
+
+var _x = 123;
+
+var myArray = ["value1"];
+
+function returnThis() {
+  return this;
+}
+
+function getTypeOf(o) {
+  return typeof(o);
+}
+
+function Foo(a) {
+  this.a = a;
+}
+
+Foo.b = 38;
+
+Foo.prototype.bar = function() {
+  return this.a;
+}
+Foo.prototype.toString = function() {
+  return "I'm a Foo a=" + this.a;
+}
+
+var container = new Object();
+container.Foo = Foo;
+
+function checkMap(m, key, value) {
+  if (m.hasOwnProperty(key))
+    return m[key] == value;
+  else
+    return false;
+}
+
+""";
+  document.body.append(script);
+}
+
+@JS()
+external bool checkMap(m, String, value);
+
+@JS('JSON.stringify')
+external String stringify(o);
+
+@JS('Node')
+external get JSNodeType;
+
+@JS('Element')
+external get JSElementType;
+
+@JS('Text')
+external get JSTextType;
+
+@JS('HTMLCanvasElement')
+external get JSHtmlCanvasElementType;
+
+@JS()
+class Foo {
+  external Foo(num a);
+
+  external num get a;
+  external num bar();
+}
+
+@JS('Foo')
+external get JSFooType;
+
+@JS()
+@anonymous
+class ExampleTypedLiteral {
+  external factory ExampleTypedLiteral({a, b, JS$_c, JS$class});
+
+  external get a;
+  external get b;
+  external get JS$_c;
+  external set JS$_c(v);
+  // Identical to JS$_c but only accessible within the library.
+  external get _c;
+  external get JS$class;
+  external set JS$class(v);
+}
+
+@JS("Object.prototype.hasOwnProperty")
+external get _hasOwnProperty;
+
+bool hasOwnProperty(o, String name) {
+  return js_util.callMethod(_hasOwnProperty, 'call', [o, name]);
+}
+
+main() {
+  _injectJs();
+  useHtmlIndividualConfiguration();
+
+  group('js_util.jsify()', () {
+    test('convert a List', () {
+      final list = [1, 2, 3, 4, 5, 6, 7, 8];
+      var array = js_util.jsify(list);
+      expect(array is List, isTrue);
+      expect(identical(array, list), isFalse);
+      expect(array.length, equals(list.length));
+      for (var i = 0; i < list.length; i++) {
+        expect(array[i], equals(list[i]));
+      }
+    });
+
+    test('convert an Iterable', () {
+      final set = new Set.from([1, 2, 3, 4, 5, 6, 7, 8]);
+      var array = js_util.jsify(set);
+      expect(array is List, isTrue);
+      expect(array.length, equals(set.length));
+      for (var i = 0; i < array.length; i++) {
+        expect(set.contains(array[i]), isTrue);
+      }
+    });
+
+    test('convert a Map', () {
+      var map = {'a': 1, 'b': 2, 'c': 3};
+      var jsMap = js_util.jsify(map);
+      expect(jsMap is! List, isTrue);
+      for (var key in map.keys) {
+        expect(checkMap(jsMap, key, map[key]), isTrue);
+      }
+    });
+
+    test('deep convert a complex object', () {
+      final object = {
+        'a': [
+          1,
+          [2, 3]
+        ],
+        'b': {'c': 3, 'd': new Foo(42)},
+        'e': null
+      };
+      var jsObject = js_util.jsify(object);
+      expect(js_util.getProperty(jsObject, 'a')[0], equals(object['a'][0]));
+      expect(
+          js_util.getProperty(jsObject, 'a')[1][0], equals(object['a'][1][0]));
+      expect(
+          js_util.getProperty(jsObject, 'a')[1][1], equals(object['a'][1][1]));
+      expect(js_util.getProperty(js_util.getProperty(jsObject, 'b'), 'c'),
+          equals(object['b']['c']));
+      expect(js_util.getProperty(js_util.getProperty(jsObject, 'b'), 'd'),
+          equals(object['b']['d']));
+      expect(
+          js_util.callMethod(
+              js_util.getProperty(js_util.getProperty(jsObject, 'b'), 'd'),
+              'bar', []),
+          equals(42));
+      expect(js_util.getProperty(jsObject, 'e'), isNull);
+    });
+
+    test('throws if object is not a Map or Iterable', () {
+      expect(() => js_util.jsify('a'),
+          throwsA(new isInstanceOf<ArgumentError>()));
+    });
+  });
+
+  group('js_util.newObject', () {
+    test('create', () {
+      expect(identical(js_util.newObject(), js_util.newObject()), isFalse);
+    });
+
+    test('callMethod', () {
+      var o = js_util.newObject();
+      expect(js_util.callMethod(o, 'toString', []), equals('[object Object]'));
+      expect(stringify(o), equals('{}'));
+    });
+
+    test('properties', () {
+      var o = js_util.newObject();
+      expect(js_util.hasProperty(o, 'foo bar'), isFalse);
+      expect(js_util.hasProperty(o, 'toString'), isTrue);
+      expect(hasOwnProperty(o, 'toString'), isFalse);
+      expect(hasOwnProperty(o, 'foo bar'), isFalse);
+      js_util.setProperty(o, 'foo bar', 42);
+      expect(hasOwnProperty(o, 'foo bar'), isTrue);
+      expect(js_util.getProperty(o, 'foo bar'), equals(42));
+      expect(js_util.hasProperty(o, 'foo bar'), isTrue);
+      expect(stringify(o), equals('{"foo bar":42}'));
+    });
+  });
+
+  group('hasProperty', () {
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.hasProperty(f, 'a'), isTrue);
+      expect(js_util.hasProperty(f, 'toString'), isTrue);
+      js_util.setProperty(f, '__proto__', null);
+      expect(js_util.hasProperty(f, 'toString'), isFalse);
+    });
+    test('typed literal', () {
+      var l =
+          new ExampleTypedLiteral(a: 'x', b: 42, JS$_c: null, JS$class: true);
+      expect(js_util.hasProperty(l, 'a'), isTrue);
+      expect(js_util.hasProperty(l, 'b'), isTrue);
+      expect(js_util.hasProperty(l, '_c'), isTrue);
+      expect(l.JS$_c, isNull);
+      expect(js_util.hasProperty(l, 'class'), isTrue);
+      // JS$_c escapes to _c so the property JS$_c will not exist on the object.
+      expect(js_util.hasProperty(l, r'JS$_c'), isFalse);
+      expect(js_util.hasProperty(l, r'JS$class'), isFalse);
+      expect(l.JS$class, isTrue);
+
+      l = new ExampleTypedLiteral(a: null);
+      expect(js_util.hasProperty(l, 'a'), isTrue);
+      expect(js_util.hasProperty(l, 'b'), isFalse);
+      expect(js_util.hasProperty(l, '_c'), isFalse);
+      expect(js_util.hasProperty(l, 'class'), isFalse);
+
+      l = new ExampleTypedLiteral(JS$_c: 74);
+      expect(js_util.hasProperty(l, '_c'), isTrue);
+      expect(l.JS$_c, equals(74));
+    });
+  });
+
+  group('getProperty', () {
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.getProperty(f, 'a'), equals(42));
+      expect(js_util.getProperty(f, 'toString') is Function, isTrue);
+      js_util.setProperty(f, '__proto__', null);
+      expect(js_util.getProperty(f, 'toString'), isNull);
+    });
+
+    test('typed literal', () {
+      var l = new ExampleTypedLiteral(a: 'x', b: 42, JS$_c: 7, JS$class: true);
+      expect(js_util.getProperty(l, 'a'), equals('x'));
+      expect(js_util.getProperty(l, 'b'), equals(42));
+      expect(js_util.getProperty(l, '_c'), equals(7));
+      expect(l.JS$_c, equals(7));
+      expect(js_util.getProperty(l, 'class'), isTrue);
+      expect(js_util.getProperty(l, r'JS$_c'), isNull);
+      expect(js_util.getProperty(l, r'JS$class'), isNull);
+    });
+  });
+
+  group('setProperty', () {
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.getProperty(f, 'a'), equals(42));
+      js_util.setProperty(f, 'a', 100);
+      expect(f.a, equals(100));
+      expect(js_util.getProperty(f, 'a'), equals(100));
+    });
+
+    test('typed literal', () {
+      var l = new ExampleTypedLiteral();
+      js_util.setProperty(l, 'a', 'foo');
+      expect(js_util.getProperty(l, 'a'), equals('foo'));
+      expect(l.a, equals('foo'));
+      js_util.setProperty(l, 'a', l);
+      expect(identical(l.a, l), isTrue);
+      var list = ['arr'];
+      js_util.setProperty(l, 'a', list);
+      expect(identical(l.a, list), isTrue);
+      l.JS$class = 42;
+      expect(l.JS$class, equals(42));
+      js_util.setProperty(l, 'class', 100);
+      expect(l.JS$class, equals(100));
+    });
+  });
+
+  group('callMethod', () {
+    test('html object', () {
+      var canvas = new Element.tag('canvas');
+      expect(
+          identical(canvas.getContext('2d'),
+              js_util.callMethod(canvas, 'getContext', ['2d'])),
+          isTrue);
+    });
+
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.callMethod(f, 'bar', []), equals(42));
+    });
+  });
+
+  group('instanceof', () {
+    test('html object', () {
+      var canvas = new Element.tag('canvas');
+      expect(js_util.instanceof(canvas, JSNodeType), isTrue);
+      expect(js_util.instanceof(canvas, JSTextType), isFalse);
+      expect(js_util.instanceof(canvas, JSElementType), isTrue);
+      expect(js_util.instanceof(canvas, JSHtmlCanvasElementType), isTrue);
+      var div = new Element.tag('div');
+      expect(js_util.instanceof(div, JSNodeType), isTrue);
+      expect(js_util.instanceof(div, JSTextType), isFalse);
+      expect(js_util.instanceof(div, JSElementType), isTrue);
+      expect(js_util.instanceof(div, JSHtmlCanvasElementType), isFalse);
+
+      var text = new Text('foo');
+      expect(js_util.instanceof(text, JSNodeType), isTrue);
+      expect(js_util.instanceof(text, JSTextType), isTrue);
+      expect(js_util.instanceof(text, JSElementType), isFalse);
+    });
+
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.instanceof(f, JSFooType), isTrue);
+      expect(js_util.instanceof(f, JSNodeType), isFalse);
+    });
+
+    test('typed literal', () {
+      var l = new ExampleTypedLiteral();
+      expect(js_util.instanceof(l, JSFooType), isFalse);
+    });
+  });
+
+  group('callConstructor', () {
+    test('html object', () {
+      var textNode = js_util.callConstructor(JSTextType, ['foo']);
+      expect(js_util.instanceof(textNode, JSTextType), isTrue);
+      expect(textNode is Text, isTrue);
+      expect(textNode.text, equals('foo'));
+    });
+
+    test('typed object', () {
+      Foo f = js_util.callConstructor(JSFooType, [42]);
+      expect(f.a, equals(42));
+    });
+  });
+}
diff --git a/pkg/dev_compiler/tool/build_sdk.dart b/pkg/dev_compiler/tool/build_sdk.dart
index 77c1a5c71b66..7041b383aebe 100644
--- a/pkg/dev_compiler/tool/build_sdk.dart
+++ b/pkg/dev_compiler/tool/build_sdk.dart
@@ -37,6 +37,7 @@ main(List<String> arguments) {
     'dart:core',
     'dart:isolate',
     'dart:js',
+    'dart:js_util',
     'dart:math',
     'dart:mirrors',
     'dart:typed_data',
diff --git a/pkg/dev_compiler/tool/input_sdk/lib/_internal/libraries.dart b/pkg/dev_compiler/tool/input_sdk/lib/_internal/libraries.dart
index 5587e5bbf12a..2814a088ceda 100644
--- a/pkg/dev_compiler/tool/input_sdk/lib/_internal/libraries.dart
+++ b/pkg/dev_compiler/tool/input_sdk/lib/_internal/libraries.dart
@@ -76,6 +76,12 @@ const Map<String, LibraryInfo> LIBRARIES = const {
       maturity: Maturity.STABLE,
       dart2jsPath: "js/dart2js/js_dart2js.dart"),
 
+  "js_util": const LibraryInfo(
+      "js_util/dartium/js_util_dartium.dart",
+      categories: "Client",
+      maturity: Maturity.STABLE,
+      dart2jsPath: "js_util/dart2js/js_util_dart2js.dart"),
+
   "math": const LibraryInfo(
       "math/math.dart",
       maturity: Maturity.STABLE,
diff --git a/pkg/dev_compiler/tool/input_sdk/lib/js_util/dart2js/js_util_dart2js.dart b/pkg/dev_compiler/tool/input_sdk/lib/js_util/dart2js/js_util_dart2js.dart
new file mode 100644
index 000000000000..a58745977906
--- /dev/null
+++ b/pkg/dev_compiler/tool/input_sdk/lib/js_util/dart2js/js_util_dart2js.dart
@@ -0,0 +1,126 @@
+// Copyright (c) 2016, 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.
+
+/// Utility methods to efficiently manipulate typed JSInterop objects in cases
+/// where the name to call is not known at runtime. You should only use these
+/// methods when the same effect cannot be achieved with @JS annotations.
+/// These methods would be extension methods on JSObject if Dart supported
+/// extension methods.
+library dart.js_util;
+
+import 'dart:_foreign_helper' show JS;
+import 'dart:collection' show HashMap;
+
+/// WARNING: performance of this method is much worse than other uitil
+/// methods in this library. Only use this method as a last resort.
+///
+/// Recursively converts a JSON-like collection of Dart objects to a
+/// collection of JavaScript objects and returns a [JsObject] proxy to it.
+///
+/// [object] must be a [Map] or [Iterable], the contents of which are also
+/// converted. Maps and Iterables are copied to a new JavaScript object.
+/// Primitives and other transferrable values are directly converted to their
+/// JavaScript type, and all other objects are proxied.
+jsify(object) {
+  if ((object is! Map) && (object is! Iterable)) {
+    throw new ArgumentError("object must be a Map or Iterable");
+  }
+  return _convertDataTree(object);
+}
+
+_convertDataTree(data) {
+  var _convertedObjects = new HashMap.identity();
+
+  _convert(o) {
+    if (_convertedObjects.containsKey(o)) {
+      return _convertedObjects[o];
+    }
+    if (o is Map) {
+      final convertedMap = JS('=Object', '{}');
+      _convertedObjects[o] = convertedMap;
+      for (var key in o.keys) {
+        JS('=Object', '#[#]=#', convertedMap, key, _convert(o[key]));
+      }
+      return convertedMap;
+    } else if (o is Iterable) {
+      var convertedList = [];
+      _convertedObjects[o] = convertedList;
+      convertedList.addAll(o.map(_convert));
+      return convertedList;
+    } else {
+      return o;
+    }
+  }
+
+  return _convert(data);
+}
+
+newObject() => JS('=Object', '{}');
+
+hasProperty(o, name) => JS('bool', '# in #', name, o);
+getProperty(o, name) => JS('Object', '#[#]', o, name);
+setProperty(o, name, value) => JS('', '#[#]=#', o, name, value);
+
+callMethod(o, String method, List args) =>
+    JS('Object', '#[#].apply(#, #)', o, method, o, args);
+
+instanceof(o, Function type) => JS('bool', '# instanceof #', o, type);
+callConstructor(Function constr, List arguments) {
+  if (arguments == null) {
+    return JS('Object', 'new #()', constr);
+  }
+
+  if (JS('bool', '# instanceof Array', arguments)) {
+    int argumentCount = JS('int', '#.length', arguments);
+    switch (argumentCount) {
+      case 0:
+        return JS('Object', 'new #()', constr);
+
+      case 1:
+        var arg0 = JS('', '#[0]', arguments);
+        return JS('Object', 'new #(#)', constr, arg0);
+
+      case 2:
+        var arg0 = JS('', '#[0]', arguments);
+        var arg1 = JS('', '#[1]', arguments);
+        return JS('Object', 'new #(#, #)', constr, arg0, arg1);
+
+      case 3:
+        var arg0 = JS('', '#[0]', arguments);
+        var arg1 = JS('', '#[1]', arguments);
+        var arg2 = JS('', '#[2]', arguments);
+        return JS('Object', 'new #(#, #, #)', constr, arg0, arg1, arg2);
+
+      case 4:
+        var arg0 = JS('', '#[0]', arguments);
+        var arg1 = JS('', '#[1]', arguments);
+        var arg2 = JS('', '#[2]', arguments);
+        var arg3 = JS('', '#[3]', arguments);
+        return JS(
+            'Object', 'new #(#, #, #, #)', constr, arg0, arg1, arg2, arg3);
+    }
+  }
+
+  // The following code solves the problem of invoking a JavaScript
+  // constructor with an unknown number arguments.
+  // First bind the constructor to the argument list using bind.apply().
+  // The first argument to bind() is the binding of 't', so add 'null' to
+  // the arguments list passed to apply().
+  // After that, use the JavaScript 'new' operator which overrides any binding
+  // of 'this' with the new instance.
+  var args = [null]..addAll(arguments);
+  var factoryFunction = JS('', '#.bind.apply(#, #)', constr, constr, args);
+  // Without this line, calling factoryFunction as a constructor throws
+  JS('String', 'String(#)', factoryFunction);
+  // This could return an UnknownJavaScriptObject, or a native
+  // object for which there is an interceptor
+  return JS('Object', 'new #()', factoryFunction);
+
+  // TODO(sra): Investigate:
+  //
+  //     var jsObj = JS('', 'Object.create(#.prototype)', constr);
+  //     JS('', '#.apply(#, #)', constr, jsObj,
+  //         []..addAll(arguments.map(_convertToJS)));
+  //     return _wrapToDart(jsObj);
+}