Adding Angular and dependent packages for testing

third_party/pkg/js/lib/src/wrapping/magic_proxy.dart

Index: third_party/pkg/js/lib/src/wrapping/magic_proxy.dart
diff --git a/third_party/pkg/js/lib/src/wrapping/magic_proxy.dart b/third_party/pkg/js/lib/src/wrapping/magic_proxy.dart
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index 0000000000000000000000000000000000000000..d20ff40cfac3bd9a1c9c634b8324e88556535424
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+++ b/third_party/pkg/js/lib/src/wrapping/magic_proxy.dart
@@ -0,0 +1,20 @@
+// 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.
+
+part of js.wrapping;
+
+/// base class to simplify declaration of [TypedProxy].
+class MagicProxy extends TypedProxy {
+  MagicProxy([Serializable<FunctionProxy> function, List args])
+      : this.fromProxy(new Proxy.withArgList(
+            function != null ? function : context.Object,
+            args != null ? args : []));
+  MagicProxy.fromProxy(Proxy proxy) : super.fromProxy(proxy);
+
+  operator[](arg) => $unsafe[arg];
+  operator[]=(key, value) => $unsafe[key] = value;
+
+  @override noSuchMethod(Invocation invocation) =>
+      $unsafe.noSuchMethod(invocation);
+}